Gerry was a Massachusetts delegate to the
Continental Congress from February 1776 to 1780. He also served from 1783 to September 1785 and was married in 1786 to Ann Thompson, the daughter of a wealthy New York merchant, 21 years his junior. In 1787 he attended the
United States Constitutional Convention and was one of the delegates voting against the new constitution (joining Mason and Randolph in not signing it). He was elected to the
U.S. House under the new national government, and served in Congress from 1789 to 1793.
He surprised his friends by becoming a strong supporter of the new government, and so vigorously supported
Alexander Hamilton's reports on public credit, including the assumption of state debts, and supported Hamilton's new
Bank of the United States, that he was considered a leading champion by the
Federalists. He did not stand for reelection in 1792. He was a presidential elector for
John Adams in the 1796 election, and was appointed by Adams to the critical delegation to France that was humiliated by the French in the
XYZ Affair. He stayed in France after his two colleagues returned, and Federalists accused him of supporting the French. He returned in October 1798, and switched his affiliation to
Democratic-Republican party in 1800.
He was the unsuccessful Democratic-Republican nominee for governor of Massachusetts in 1800, 1801, 1802 and 1803. In 1810 he was finally elected
Governor of Massachusetts as a Democratic-Republican. He was re-elected in 1811 but defeated in 1812 over his support for the redistricting bill that created the word
gerrymander. He was chosen as vice president to
James Madison. He died in office in
Washington, D.C. and is buried there in the
Congressional Cemetery.