Thomas Walker Gilmer was born on 6 April 1802 in Albemarle County, Virginia. He studied law and, after a brief residence in Missouri, practiced that profession in Charlottesville, Virginia. Gilmer also owned and edited a newspaper in that city and was politically active. He supported the aspirations of Andrew Jackson and represented Albemarle County in the Virginia House of Delegates. In 1834, Gilmer broke with Jackson and joined the Whig party. He became state Governor in 1840, pursuing a strong states' rights policy while in office.

Elected to the U.S. Congress in 1841, Gilmer left the Whigs, returned to the Democratic Party, and emerged as a strong supporter of President John Tyler. In February 1844, Tyler nominated him to be Secretary of the Navy. On 28 February 1844, after only nine days in office, Secretary of the Navy Thomas Gilmer was one of several dignitaries killed when a cannon exploded on board the steamer USS Princeton.

USS Gilmer (DD-233, later APD-11), 1920-1946, was named in honor of Secretary of the Navy Gilmer.