Robert Morris was born on January 31, 1734, in Liverpool, England. Information on Morris's mother is non-existent, much like his relationship with her. Morris arrived in America with his father, Robert Morris Sr., at the age of 13. While his father worked as a tobacco exporter in the town of Oxford, Maryland, Morris was taken to Philadelphia by Robert Greenway, who was a merchant and friend of Robert's father. After a failed attempt at schooling, Greenway introduced Morris to the business world. Greenway landed Morris an apprenticeship at a shipping and banking firm. Morris adapted very quickly to the operations of the company and immediately impressed his boss Charles Willing. However, things became grim for Morris when he learned that his father died after being wounded by a shot that was fired in his honor and contracted blood poisoning as a result.

In 1754, Robert Morris's career began to take off. At age 20, Morris became a partner at the firm where he was working with Thomas Willing, who had also become partner after his father Charles died. Together, the pair helped Willing, Morris and Co. become one of the largest and wealthiest firms in the country. The Stamp Act was passed in 1765, and the act surely had a negative impact on Willing, Morris and Co. Even though he was a born an Englishman, Morris insisted that the act be repealed and, as a result, extended his career into the world of politics. In 1769, at the age of 35, Morris married 20-year-old Mary White. Together, the two had five sons and two daughters. In 1775, Morris was elected to represent Pennsylvania in the Second Continental Congress.

Morris immediately began to make waves in Congress as soon as the Revolutionary War began. He was named vice-president of the Pennsylvania Council of Safety, and he was also called upon many times to share his knowledge of commerce and navigation. Willing, Morris and Co. was also involved in a contract to provide imports of arms and ammunition for the war. In July 1776, Morris was at the center of controversy because of his stance against drafting a Declaration of Independence. While other Pennsylvanians lost their Congressional seats for voting against the Declaration, Morris was spared from losing his seat because his services became too valuable to give up at a time when a new government was taking shape. In a letter explaining his actions, Morris proclaimed that "it was an improper time" for America to try and separate itself from Great Britain. However, Morris eventually signed the Declaration of Independence on August 2, 1776.

Morris became a hero during the Revolutionary War when Congress fled to Baltimore, Maryland. Morris was left in charge and helped protect the city of Philadelphia at a time when it was in severe distress. Morris also utilized his financial skills to obtain money to help strengthen the troops for key battles in the war. In 1778, things took a turn for the worse after Morris signed the Articles of Confederation.

His public image as a member of the Pennsylvania legislature was damaged in 1779 when a possible conflict of interest came into question. Morris was accused of making profits from private business ventures that were made in the name of the government. Morris fought with sheer resolve over these charges and was eventually acquitted. In the end, he was no longer in public office. However, his services were too valuable, and he eventually made it back into the legislature after helping supply the troops with lead for weaponry. Morris even went so far as to risk his own finances to help strengthen Washington's army in important battles.

From 1781 to 1784, Morris served as Superintendent of Finance, a job that allowed him to hold great power and control over the perilous economic situation that the United States was in. In order to cover some of the war debts, Morris proposed the creation of a national bank. The Bank of North America, the first financial institution chartered by the United States, opened for business in 1782 with none other than Morris's old business partner Thomas Willing, who was appointed its first president. One important document that Morris was responsible for writing was entitled "On Public Credit." This was a proposed economic system for the country that set the precedent for a similar proposal by Treasury Secretary Alexander Hamilton. Morris also wrote what would later be published as The Papers of Robert Morris. It is an in-depth look at several letters and diary entries he wrote to George Washington and other politicians concerning the political and economic affairs of America during his time as Superintendent. He expressed both strong assent and tacit dissent for many of the laws and acts that were either passed or in the process of going through legislation.

Morris's accolades continued to accrue in 1787 when he was selected alongside Benjamin Franklin to represent Pennsylvania at the Constitutional Convention after expressing a strong desire to draw up a constitution for the country. His most memorable year was in 1788, when Morris not only was chosen to become one of the signers of the Constitution of the United States, but also was elected (along with William Maclay) to become one of the first two Senators ever to represent Pennsylvania. With all of these feathers in his cap, Morris turned down the opportunity to become Secretary of the Treasury, instead conceding the position to Alexander Hamilton. Morris only served one term in the Senate, but in that time he played a strong role in the debates over several economic issues plaguing the United States.

When Morris left public office in 1794, he began other business ventures, including a canal company that became one of the first organizations to advance improvements in Pennsylvania. He later went into land speculation and cut ties with his old company Willing, Morris and Co. after Thomas Willing suggested that he withdraw because of the risky business Morris was engaging in. Robert Morris became arguably the largest private property owner in the history of the United States, possessing well over six million acres of land in seven states. This all came at a steep price that caught up to Morris eventually. Creditors began to pursue Morris about his purchases, and his land slowly was sold piece by piece to pay them back. Morris was indebted to many people, and it got to the point where Morris actually fled to his country estate, also known as "The Hills," to hide from creditors. He left an unfinished mansion behind in Philadelphia, which would famously become known as "Morris's Folly." Morris even contemplated suicide before realizing it would be terrible for his wife and children. He turned himself in on February 14, 1798, and was eventually sent to debtor's prison. One person that stuck by Morris and kept in touch with him in prison was George Washington. Thomas Jefferson even considered giving Morris a spot in his cabinet if he got out of prison in time. Congress passed a Bankruptcy Act in 1800, and Morris gained freedom a year later with almost $3 million in debt still to his name.

Morris pursued small business ventures, but he eventually became ill and retired. He remained in Philadelphia until he passed away on May 8, 1806. He was buried in the family vault in Christ Churchyard in Philadelphia.