He served as John Quincy Adams's running mate on the National Republican ticket during the 1828 United States presidential election.

He served as the acting Secretary of State briefly in 1817 and negotiated the Rush–Bagot Treaty, which limited naval forces on the Great Lakes.

He negotiated the Treaty of 1818 which set the boundary between the U.S. and Canada and had discussions with George Canning that led to the announcement of the Monroe Doctrine.

[3] They were the parents of eleven children including the lawyer and writer Benjamin Rush and Union Army colonel Richard H.

[4] As a lawyer, Rush first gained attention with a speech he gave which condemned the British naval attack during the Chesapeake-Leopard affair.

[8] In October 1817, Rush was appointed Minister to Britain[9] to succeed John Quincy Adams, who had taken the position of Secretary of State upon his return.

[5] In 1829, he went overseas at the behest of the cities of Alexandria, Virginia, and Georgetown, to secure funds for the construction of a canal connecting the Chesapeake Bay and the Ohio River.

[11] In 1836, President Andrew Jackson sent him to England as Commissioner to secure for the United States the legacy left the government by James Smithson.

[15] During the 1820s, Rush was a member of the prestigious society, Columbian Institute for the Promotion of Arts and Sciences, who counted among their members former presidents Andrew Jackson and John Quincy Adams and many prominent men of the day, including well-known representatives of the military, government service, medical and other professions.

[17][18] Five United States Coast Guard vessels were named in his honor: The USCGC Rush (WMSM-918) Heritage-class cutter[24] is under construction and scheduled for delivery in 2026.