John Sherman (May 10, 1823 – October 22, 1900) was an American politician from Ohio who served in federal office throughout the Civil War and into the late nineteenth century. A member of the Republican Party, he served in both houses of the U.S. Congress. He also served as Secretary of the Treasury and Secretary of State. Sherman sought the Republican presidential nomination three times, coming closest in 1888, but was never chosen by the party. Between 1861-1897, John Sherman served in the U.S. Senate for nearly 32 years and holds the record for longest serving senator from the state of Ohio (1861–1877; 1881–1897).
Born in Lancaster, Ohio, Sherman later moved to Mansfield, Ohio, where he began a law career before entering politics. He was the younger brother of Union general William Tecumseh Sherman, with whom he had a close relationship. Initially a Whig, Sherman was among those anti-slavery activists who formed what became the Republican Party. He served three terms in the House of Representatives. As a member of the House, Sherman traveled to Kansas to investigate the unrest between pro- and anti-slavery partisans there. He rose in party leadership and was nearly elected Speaker in 1859. Sherman was elected to the Senate in 1861. As a senator, he was a leader in financial matters, helping to redesign the United States' monetary system to meet the needs of a nation torn apart by civil war. He also served as the chair of the Senate Agriculture Committee during his 32 years in the Senate. After the war, he worked to produce legislation that would restore the nation's credit abroad and produce a stable, gold-backed currency at home.