John Peter Gabriel Muhlenberg was born on October 1, 1746, in Trappe, Pennsylvania. His early education was supplemented at the Philadelphia Academy (University of Pennsylvania). At the age of 18, he was sent with two brothers to Halle, Germany, for further education. Muhlenberg was apprenticed to a grocer in Lubeck. Ill-treated, he ran away and joined an English regiment that saw action in the French and Indian War. He returned to Philadelphia in 1767 and was discharged.
Muhlenberg's father then persuaded him to study for the ministry. Accepting a call in 1771 to a congregation in Woodstock, Virginia, Muhlenberg first traveled to England to be ordained in the Church of England. His work led him into politics, and he served in the House of Burgesses in 1774. Over the next two years he became involved with the local leaders of the Revolution. In 1776 he left Woodstock and raised a regiment from the Shenandoah Valley. Muhlenberg was quickly commissioned a brigadier general in the Continental Army and was active in many battles. He was brevetted major general in 1783.
Returning a hero, he was elected to the Supreme Executive Council in 1784 and served as Pennsylvania's vice president from 1785 to 1788. He was elected to the First Congress (1788-1789), of which his brother Frederick was Speaker, and served in several successive Congresses. Elected to the Senate in 1801, he resigned shortly thereafter to accept the appointment of supervisor of revenue for Philadelphia. He served in this post until his death on October 1, 1807.