David Rittenhouse was born on April 8, 1732 in Germantown, Pennsylvania. He was the second child, and first son, of Matthias and Elizabeth Rittenhouse. Little has been recorded about the earlier years of David Rittenhouse's life. It is known, however, that when he was just eight years old, he made a wooden model of a water mill. When he was sixteen, Rittenhouse built a wooden clock and a few years later he built a brass clock. During this time, one of his greatest influences was his uncle David Williams.

When his uncle died, he left his nephew a box that contained carpentry tools and some books about elementary geometry and arithmetic, along with pages of calculations. Rittenhouse said that this box was a "great treasure," especially since he had little access to other books or education. When Rittenhouse was nineteen, he began his career as a clockmaker. His father allowed him to build a shop on the family farm along the road into town. Rittenhouse continued working as a clockmaker up until the Revolutionary War. While working as a clockmaker, Rittenhouse also studied a number of different sciences on his own. During these studies, Rittenhouse began working on building a telescope, compasses, and levels.

In 1763, the secretary to the governor of Pennsylvania, the Reverend Richards Peters, asked Rittenhouse to help determine the boundary between Pennsylvania and Maryland. He was well paid for the small amount of physical effort that was required to complete this job; however, the lack of manual labor was offset by the mental taxation of the task. About this job, Rittenhouse said, "I found it a very laborious affair; being obliged, singly, to go through a number of intricate calculations." Because Rittenhouse's method was so accurate, Charles Mason and Jeremiah Dixon used it to create their famous "Mason-Dixon" line. The next year, Rittenhouse's father gave him the family homestead when Matthias Rittenhouse bought a new farm in Worcester Township.

Rittenhouse married Eleanor Coulston, a Quaker, on February 20, 1766. This marriage, done away from the Quaker faith, caused Eleanor to be shunned by the Quaker Society. Almost a year and a half after the ceremony, Eleanor apologized to the Meeting and was subsequently readmitted to the Society on a probationary basis. Eleanor remained a practicing Quaker for the rest of her life. The couple had their first child on January 23, 1767. They named their daughter Elizabeth, after David's mother. Around this time, Rittenhouse began using his knowledge of astronomy to begin the construction of a planetarium. However, his lack of formal education kept his achievements from being recognized. Fortunately, Reverend William Smith, who was provost of the College of Philadelphia, took it upon himself to help Rittenhouse. In his position as provost, he was able to convince the trustees and faculty to award Rittenhouse an honorary Master of Arts Degree.

In his commencement speech on November 17, 1767, Rev. Smith praised Rittenhouse for "extraordinary Merit, and the vast Progress and Improvement...made by a Felicity of native Genius, in Mechanics, Mathematics, Astronomy and liberal Arts; all...adorned by singular modesty and irreproachable Morals." June 3, 1769 presented an interesting opportunity for Rittenhouse. On this date, the transit of Venus was observable. This opportunity would allow for the calculation of the distance in miles to the sun. With this value, astronomers would be able to calculate the relative distances within the solar system. In preparation, Rittenhouse began to build an observatory to hold his telescope, clock, and other accessories. The task required construction of a new telescope, one that contained three hairs at its focus. The new telescope, which Rittenhouse placed on a stone pedestal, would show at what time the sun reached the same altitude in the afternoon as it had in the morning. Rittenhouse then constructed a smaller, meridian telescope that was able to rotate.

When it came down to the moment of the transit, Rittenhouse, who had suffered from what was believed to be an ulcer, became so anxious that he passed out. This fainting was the result of pressure to prove his credibility as an expert astronomer. In the end, his predictions about solar system distances were proven correct, which allowed Rittenhouse to become an internationally known astronomer. The findings from this transit were sent to Benjamin Franklin, then president of the American Philosophical Society. The Society thought so highly of Rittenhouse that they felt he should succeed Franklin as president.

In 1770, Rittenhouse moved his family to the city of Philadelphia. He leased a house on the outskirts of the city, within walking distance of the business districts. After the move, Rittenhouse became known as the greatest instrument maker in Philadelphia. In the same year, he completed two planetariums, one for the College of Philadelphia and the other for what would become Princeton University. This feat was honored with a monetary reward from the Pennsylvania Assembly, and Princeton awarded Rittenhouse a degree of Master of Arts. Unfortunately, Rittenhouse's achievement was overshadowed by personal tragedy. During the construction of the planetariums, Rittenhouse's wife Eleanor died after giving birth to a stillborn child. Rittenhouse admitted to a friend, "This would have been very agreeable to me, if my poor Eleanor had lived; but now, neither money—nor reputation—has any charms; though I must still think them valuable, because absolutely necessary in this unhappy life."

The end of 1772 brought happier times to Rittenhouse. He married a longtime friend, Hannah Jacobs. Hannah, like Eleanor, was also a member of the Society of Friends who was disowned by the Quakers after her marriage. Unlike Eleanor, Hannah did not try to become reinstated. In fact, she often accompanied her husband to Presbyterian services. In 1773, Rittenhouse began providing calculations of the rising and setting of the sun as well as the length of days and movements of the planets for James Humphreys' Universal Almanack. Humphreys knew that Rittenhouse's name would bring respect to his work. Soon other almanacs were seeking Rittenhouse's calculations. These included The Virginia Almanack, Father Abraham's Almanack, and Father Abraham's Pocket Almanack.

With the start of the Revolution, Rittenhouse saw a change in his life. He was extremely committed to the Revolution and had always favored a representative form of government. The Second Continental Congress created a Committee of Safety to oversee safety measures. One provision included the construction of a group of row galleys. The galleys were demonstrated on September 28 to the Congress, the Assembly, and leading citizens of Philadelphia—which included David Rittenhouse. Aboard one of the boats, Rittenhouse found himself in the company of John Adams. In his diary, Adams wrote, "Rittenhouse is a mechanic; a mathematician, a philosopher, and an astronomer...[he] is a tall slender man, plain, soft, modest, no remarkable depth or thoughtfulness in his face, yet cool, attentive, and clear."

On October 27, the Committee of Safety appointed Rittenhouse as its engineer. On March 2, 1776, Rittenhouse was elected to fill the Pennsylvania Assembly seat of Benjamin Franklin. Franklin had resigned his seat along with his position on the Committee of Safety in order to concentrate fully on being a member of the Continental Congress. In the same year, the Committee of Safety was renamed the Council of Safety. After this renaming, the Council elected Rittenhouse vice president. The president, Thomas Wharton, was often out of town, leaving Rittenhouse in charge of the Council on a regular basis, which led to Rittenhouse's appointment as President of the Council of Safety the following year. On July 8, 1776, Rittenhouse was elected to be a member of the Convention drafting a new Pennsylvania constitution. Following this appointment, Rittenhouse was unanimously chosen by the Assembly to fill the position of treasurer of the Continental Congress.

Rittenhouse was thus a key part of framing the Pennsylvania Constitution of 1776. He was a member of the committee that created the declaration of rights, the committee that created the preamble and oaths, and he was chair when the frame of government was drafted. The former Pennsylvania Treasurer, Michael Hillegas, was appointed Treasurer of the Continental Congress. Since the Congress was forced to relocate to Baltimore to avoid advancing British forces from 1776 through 1777, Hillegas followed suit. However, he took the Pennsylvania Treasury with him. This left the Assembly with not only an absent treasury, but also a vacant treasurer position. The Assembly met on January 13, 1777 for a quorum and went over the report of the Committee on the Treasury. The next day, the Assembly unanimously elected Rittenhouse to the position of Treasurer of the Commonwealth. Even after assuming this position, which was the third highest ranking executive position in the state, Rittenhouse did not give up his position on the Council of Safety. He continued with as much vigor as before. To eliminate the Council of Safety, the Assembly began taking members of the Council of Safety and placing them on the Supreme Executive Council—this included Thomas Wharton, chairman of the Council of Safety.

On March 13, 1777, the Supreme Executive Council eliminated the Council of Safety entirely and replaced it with the Board of War, which held much less power than the Council of Safety had. Rittenhouse was named first of nine members to be named to the Board of War. The Board gradually became even less powerful and Rittenhouse was so preoccupied with the Treasury problems that he began to attend the Board of War meetings less and less. On August 6, 1777, less than five months after its creation, the Board of War was done away with altogether. In September of 1777, with the approach of the British toward Philadelphia, the capital was moved to Lancaster. With this relocation, Rittenhouse was asked to transfer all state monies to Lancaster, while he himself moved in with a friend, William Henry. During this time, the Assembly created a new Council on Safety in order to oversee emergency issues and keep the Commonwealth preserved. Rittenhouse was named to this Council along with the members of the Supreme Executive Council. They were given full power to intervene in almost any manner in order to protect the Commonwealth.

Rittenhouse was at the center of three very important events during 1779. First, after a few years without meetings, he was able to call a meeting to discuss the state of the American Philosophical Society. At this meeting, elections were held for officers in the Society. Benjamin Franklin remained president, but the absence of two of the former vice presidents allowed for Rittenhouse to be elected as one of the vice presidents. Previously, Rittenhouse had been secretary, curator, and librarian for the Society. In this position of vice president, Rittenhouse began to push for more activity by the Society.

Second, in August, Rittenhouse was asked to determine the boundary for Virginia, mainly because Thomas Jefferson was now the governor of Virginia and he respected Rittenhouse's previous work. Rittenhouse's outlined boundaries were accepted by Pennsylvania in December of 1780. Third, Rittenhouse was selected as professor of astronomy at the newly renamed University of the State of Pennsylvania, formerly the College of Philadelphia. In February 1780, David Rittenhouse was given the new title of vice-provost at the University of the State of Pennsylvania (now known as the University of Pennsylvania). Rittenhouse was excited about these opportunities because he would finally be able to focus on science. However, these new plans for the University never occurred. Rittenhouse neither taught the proposed courses nor collected a paycheck, despite his status as a trustee of the University from 1779 to 1780 and again from 1782 to 1796. In 1781, at the urging of some of Rittenhouse's political friends, the Assembly gave money to Rittenhouse to construct a new observatory. Rittenhouse decided to create the new observatory closer to him, constructing it on the corner of Seventh and Mulberry Streets.

In 1783, it is believed that Rittenhouse manufactured a vernier compass and gave it to George Washington. This vernier compass was different from other compasses in that it had a ring with graduated degrees that could be rotated. The new construction allowed for more accuracy in the reading of the compass. From this point on, vernier compasses became known as "the Rittenhouse compass." Another new creation that was attributed to Rittenhouse was the "Rittenhouse stove" in 1784. This new stove replaced the Franklin stove. The stove itself was made of cast iron and was more open and simple than the Franklin stove. The central part of the stove was inclined toward the floor at a ten-degree angle, which allowed for more heat to radiate throughout the room.

The spring of 1784 brought another surveying opportunity for Rittenhouse. He was named first to the commission to make the Schuylkill River navigable. One of the most important aspects of this project was the Susquehanna-Schuylkill survey. After conducting this survey, Rittenhouse and his companions reported to the Assembly that canals could be constructed to allow for water travel from Philadelphia to the western part of the state. This report gave rise to the increase in canal enterprises in the 1790's. Toward the end of 1784, David Rittenhouse received a master's degree from the College of William and Mary. Also at this time, Rittenhouse and some other members of the Philosophical Society began to acquire land at State House Square and create a building fund to build a new hall.

Finally, Rittenhouse took on an expedition, which ended in August, to survey and to establish the northern and western borders of Virginia. A new society, the Pennsylvania Society for the Encouragement of Manufacturers and the Useful Arts, was created in 1787. Tench Coxe, who was the leading publicist behind this new movement, greatly respected Rittenhouse. This admiration led Rittenhouse to be nominated for president of the new Society. However, at the last minute he was replaced by Thomas Mifflin. In the end, Rittenhouse became the first vice-president of this Society. Due to this perceived slight, he took little interest in the Society and did not run for re-election. The Assembly election of November 1787 was a huge defeat for Constitutionalists like Rittenhouse. Both he and Benjamin Franklin lost to the Republicans. The whole debate was centered on feelings about the new constitution that was being created in Philadelphia during the Federal Convention. From 1787 to 1790, Rittenhouse found himself in an unfavorable political climate. There were multiple attacks on the poor state of the Treasury and much of it was focused on Rittenhouse, even though critics commended his integrity. Rittenhouse requested reappointment and won unanimously.

Adding to an already impressive resume, on September 24, 1788, Rittenhouse began to record all meteorological and astronomical events, which he recorded from his observatory. This activity continued for the rest of his life. Another accomplishment during this time of political instability was that Rittenhouse received an LL.D from the College of New Jersey in September of 1789. From this point on, he was known as "Dr. Rittenhouse." On November 9, 1789, Rittenhouse submitted his resignation as treasurer to the legislature. In this letter, Rittenhouse stated that his reasons for resigning were his poor health and his interest in astronomy. Also, he made sure to thank the Assembly for the honor of reappointing him for thirteen years. Within the letter, Rittenhouse asked that any problems during his tenure should be "imputed to want of ability, and not of integrity." Unfortunately, the Assembly did not give Rittenhouse the honor he deserved. Instead of commenting on his service or his role in the Revolution, the Assembly merely entered the letter into the minutes.

The year 1790 did not start off any better for Rittenhouse. One of his closest friends and mentor of sorts, Benjamin Franklin, died on April 17. Rittenhouse was given the honor of being one of the pallbearers. He joined Thomas Mifflin, the president of the Commonwealth; Thomas McKean, Pennsylvania's chief justice; Thomas Willing, president of the Bank of America; Samuel Powel, mayor of Philadelphia; and finally, William Bingham, Philadelphia's most distinguished leader in economics, in the duties of carrying Franklin's casket.

In January of 1791, the American Philosophical Society chose Rittenhouse to be the new president. He was greatly honored by this new position. To the Society, he said, "I am extreamly (sic.) sensible of the Honour the members of the Philosophical Society have done me by electing me their President, in the room of that very worthy patron of the Society, the late Doctor Franklin." After this election, Rittenhouse made an effort to be more involved in the society, attending meetings even though his health was failing. President George Washington bestowed another honor on Rittenhouse by naming him Director of the United States Mint on April 14, 1792. This appointment was the result of a number of factors. First and foremost was the fact that Rittenhouse was called on to advise Robert Morris, the superintendent of finance in 1782, about the machinery he was trying to get Congress to approve in 1782. Also, Thomas Jefferson was Secretary of State and was able to stop efforts to take the production of American coins overseas. At first Rittenhouse hesitated to accept this appointment. He was concerned about his health affecting his job performance and his past experience with the Treasury had detrimentally impacted his confidence.

On July 1, Rittenhouse took the oath of office and then on July 9 he gave formal acceptance and stated that it was only "for the present." He also expressed his thanks for the honor that was bestowed upon him. Rittenhouse purchased land on Seventh Street between Mulberry and Market to be the new home for the Mint. Then on July 31, the foundation for the new Mint was laid. At the insistence of Washington, the Mint was under the control of the State Department and not the Treasury Department. The Mint experienced an increase in expenses at the beginning of 1795, mainly because the Mint was responsible for refining its own silver. As the year drew to an end, many people began criticizing the Mint. Joshua Coit of Connecticut introduced a resolution to the House of Representatives on December 9 which asked for an investigation of the Mint. Elias Boudinot was made the chairman of the investigation committee and he found overall that the Mint was only beneficial to the region around Philadelphia. However, after several outside reviews, Boudinot stated that the real problem had nothing to do with Rittenhouse. After the final report was submitted, Rittenhouse stated his intent to resign effective June 30, 1795.

During this time, Rittenhouse's health began to decline and he slowly started to withdraw from his other obligations. Even though he was still president of the Philosophical Society, he rarely went to meetings. However, he did receive one of the highest awards from Britain: he was elected on the foreign list to the Royal Society of London. Membership in the Royal Society was the premier award in the scientific arena. Rittenhouse was one of just two Americans that were given this honor between the Revolutionary War and 1800. Phineas Bond, the British consul in Philadelphia, awarded Rittenhouse this honor in June 1795. Even though he was withdrawing from work, Rittenhouse did accept a number of new positions which included chairman for the committee to plan a lottery for the state of Pennsylvania. The lottery was to be created in order to help the large canal companies. The $400,000 that was expected to be raised would allow the construction of the canals to continue. Also, Rittenhouse became one of three state commissioners that inspected gunpowder. He even helped with the plans for the building that would be home to the activities of the inspector of gunpowder.

In April of 1796, Rittenhouse ran as a presidential elector for Thomas Jefferson. Throughout the year, Rittenhouse was often ill, though not seriously. He had stated on multiple occasions that he felt his career was to come to an end. On June 22, 1796, Rittenhouse suffered an attack so bad a doctor was called. He was diagnosed with cholera; however the symptoms, including increased pain in the stomach area, and fever continued to get worse. The next day, Dr. Adam Kuhn was summoned and ended up drawing blood, even though Rittenhouse had had a lifelong opposition to the practice of bloodletting. Rittenhouse said he felt "relief" after the procedure but also he expressed his belief that he was not going to make it through this ordeal. Rittenhouse was increasingly more short-tempered because of the pain and the fact that he knew he was dying.

On June 25, Rittenhouse became much worse. Around midnight on June 26, he became delirious, causing his wife Hannah to leave the room, where she had been reading the sermon "on the Goodness of God" at Rittenhouse's request. At ten minutes to two, with his daughters at his side, David Rittenhouse passed away. In his eulogy to Rittenhouse, Benjamin Rush said: The friend of God and man, is now no more!-For this, the temple of Science is hung in mourning,-for this, our eyes now drop a tributary tear. Nor do we weep alone.-The United State of America sympathize in our grief, for his name gave a splendor to the American character, and the friends of humanity in distant parts of the world unite with us in lamenting our common loss,-for he belonged to the whole human race. Much of Rittenhouse's written work was lost after his death. However, Rittenhouse does have other lasting legacies. When William Penn designed the city of Philadelphia, he included in the plans five squares. One of these squares, known as the "Southwest Square" was renamed "Rittenhouse Square" in 1825, in honor of Rittenhouse's memory. It became a prestigious place to live and it is still an enjoyable place to visit while in Philadelphia.