Frederick Augustus Conrad Muhlenberg was born on January 1, 1750, in what is now Trappe, Pennsylvania. Muhlenberg was the second of three sons and part of a family that distinguished itself in early American history. Muhlenberg's father, Henry Melchior Muhlenberg, was a minister to German Lutheran colonists in southeastern Pennsylvania and is considered a father of the Lutheran Church in the United States. Muhlenberg College in Allentown, Pennsylvania, was named after Henry Melchior Muhlenberg. Frederick Muhlenberg's younger brother, Gotthilf Henry Ernestus Muhlenberg, was the first president of Franklin College (now Franklin and Marshall College), and his older brother, John Peter Gabriel Muhlenberg, was colonel of the Eighth Virginia Regiment at the start of the American Revolution, a general at the war's end, and a politician after the war. Though John Peter Gabriel Muhlenberg held positions as a congressman and briefly as a senator, it was Frederick Muhlenberg who rose to political prominence.

Muhlenberg's birth highlighted some tension in his parents' marriage. In his journal, Muhlenberg's father Henry wrote, "On the evening of New Year's Day, when I had to be away from home owing to pastoral duties, the gracious God delivered my wife and granted us a healthy and well-formed son. In her anguish my wife wept over the fact that her husband was so seldom at home and that he was away just at this time. She felt the wife of a workman or farmer was better off than she." His father Henry named Muhlenberg after two "Reverend Fathers," hoping that "when the Reverend Fathers read these lines they will send up to the Holy of Holies for the poor child a little prayer that he may not perish but have everlasting life."

In 1761, when Muhlenberg was 11, the family moved to Philadelphia, Pennsylvania. Two years later, his father Henry sent Muhlenberg and his brothers to Germany to be educated. In April, the boys sailed from Philadelphia to London and then to Rotterdam, eventually arriving on September 1 in the city of Halle, the same city their father had left from for America eighteen years earlier. In Halle, Muhlenberg began studying in preparation to become a Lutheran minister. He studied Latin, Greek, logic, theology, history and music. After seven years in Halle, Germany, Muhlenberg returned home with his younger brother Henry, arriving in Philadelphia on September 26, 1770. Muhlenberg worked as a Lutheran preacher, giving his first sermon on October 7 and becoming ordained on October 25. He began to work in what is now Schaefferstown, Pennsylvania, splitting his time among five churches in the area.

On October 15, 1771, less than a year after his ordination, Muhlenberg married Catharine Schaeffer, the daughter of a Philadelphia sugar merchant. The couple returned to Muhlenberg's home, but two years later left the rural Tulpehocken Valley for an appointment at a church in burgeoning New York City. However, the Revolutionary War soon began, which swept Muhlenberg from his position as minister into his role as a politician.

At first, Muhlenberg was unsure of how to respond to the growing threat of war. A British bombardment of New York City in 1775 forced his wife and children to leave the city, but correspondence between Muhlenberg and his brother Peter reveals Muhlenberg's feelings about mixing his religious vocation with his political opinion: "You have become too involved in matters which, as a preacher, you have nothing whatsoever to do..." The two exchanged more letters, in which Peter accused Muhlenberg of being a Tory sympathizer, and Muhlenberg responded with his convictions that man cannot serve two masters. Repeated unrest seemed to convince Muhlenberg to change his mind. He left New York, but tension in southeastern Pennsylvania caused him to move his family deeper into the Pennsylvania countryside, to New Hanover. Two years later he began to doubt his occupation in the church. Muhlenberg then became a politician.

On March 3, 1779, Frederick took a seat in the Continental Congress and that fall he entered the Pennsylvania Assembly. In 1780, his political career took off when he was elected Speaker of the Pennsylvania Assembly. Muhlenberg's father Henry was disappointed in his son's new occupation, but Muhlenberg continued with the course he had chosen. In 1787, he was elected president of the Pennsylvania convention for the ratification of the Constitution. A year later, he was elected to the first Congress, receiving the greatest number of votes of any Pennsylvania candidate. In that same Congress, Muhlenberg was elected the first Speaker of the House of Representatives of the United States, winning twenty-three of the thirty votes cast.

A combination of political interests and personal qualifications helped Muhlenberg win the vote. At this point, Virginia and Massachusetts had already won the biggest constitutional prizes: president and vice president. The location of the national capital had to be determined, and states in the middle of the new country, like Maryland, New Jersey, and Pennsylvania, had the strongest claims to the capital. A delegation from Pennsylvania caucused to discuss the speakership, and Muhlenberg was the delegation's first choice. He now had a group of lobbyists. Furthermore, Muhlenberg had the r??sum?? for the position. He had already served as Speaker of the House in his state, as the President of Pennsylvania's convention to ratify the Constitution. He had also served in the Continental Congress. When his qualifications were coupled with the political landscape, Muhlenberg emerged as the clear winner in the election. His position had no precedent, and in the absence of well-defined parties, Muhlenberg navigated between his political obligations and an obligation to remain somewhat removed from partisanship.

The rest of Muhlenberg's political career was filled with various events of merit. He was a member of the first four Congresses, and elected Speaker for the first and third. In 1793, he ran for Governor against incumbent and inaugural Governor Thomas Mifflin; Muhlenberg lost the election. In 1794, he cast a deciding vote in favor of the Jay Treaty, an agreement that tied up some economic loose ends from the American Revolution with Great Britain. Opponents of the agreement thought it kowtowed to the British too much, and public opinion of Muhlenberg dropped as a result of his vote. Two years later, he was defeated in another run for Congress.

After his four terms in Congress, Muhlenberg was appointed Receiver General of the Pennsylvania land office, a position similar to treasurer, by then governor Thomas McKean. He moved to Lancaster, Pennsylvania, but only lived there for a short time. A year after his appointment, he died of apoplexy on June 4, 1801.