In June of 1776 he was elected to attend the provincial conference to send delegates to the Continental Congress. He was appointed to represent Philadelphia that year and so signed the Declaration of Independence. In 1777 he was surgeon-general of the middle department of the Continental Army. This office led to some trouble for him; he was critical of the administration of the Army Medical service under Dr. William Shippen. He complained to Washington, who deferred to the Congress. Ultimately Congress upheld Shipping and Rush resigned in disgust. As the war continued and Army forces under General Washington suffered a series of defeats, Rush secretly campaigned for removal of Washington as commander in chief, and went so far as to write an anonymous letter to then Governor Patrick Henry of Virginia. He was caught in the act and confronted by Washington, at which point he bowed out of any activities related to the war. In 1789 he wrote newspapers in Philadelphia in favor of adopting the Federal constitution. He was then elected to the Pennsylvania convention which adopted that constitution. He was appointed treasurer of the US Mint where he served from 1797
In June of 1776 he was elected to attend the provincial conference to send delegates to the Continental Congress. He was appointed to represent Philadelphia that year and so signed the Declaration of Independence. In 1777 he was surgeon-general of the middle department of the Continental Army. This office led to some trouble for him; he was critical of the administration of the Army Medical service under Dr. William Shippen. He complained to Washington, who deferred to the Congress. Ultimately Congress upheld Shipping and Rush resigned in disgust. As the war continued and Army forces under General Washington suffered a series of defeats, Rush secretly campaigned for removal of Washington as commander in chief, and went so far as to write an anonymous letter to then Governor Patrick Henry of Virginia. He was caught in the act and confronted by Washington, at which point he bowed out of any activities related to the war. In 1789 he wrote newspapers in Philadelphia in favor of adopting the Federal constitution. He was then elected to the Pennsylvania convention which adopted that constitution. He was appointed treasurer of the US Mint where he served from 1797