Hannibal Hamlin (August 27, 1809 - July 4, 1891) was an American politician from the U.S. state of Maine. Hamlin served in the Maine Legislature, the U.S. House of Representatives, the U.S. Senate and as Governor of Maine. Hamlin began his career as a Democrat but later became a member of the Republican Party. He was the first Republican to serve as Vice President of the United States, elected as Abraham Lincoln's running mate in the 1860 presidential election.
Hamlin was born in the Paris Hill district of South Paris, Maine, in Oxford County. He attended the district schools and Hebron Academy there, and later managed his father's farm. For the next few years he worked at several jobs: schoolmaster, cook, woodcutter, surveyor, manager of a weekly newspaper in Paris, and a compositor at a printer's office. He studied law and was admitted to the bar in 1833. He began practicing in Hampden, where he lived until 1848.
The political career of Hamlin began in 1836, when he began a term in the Maine House of Representatives after being elected the year before. He served in the Aroostook War, which took place in 1839. Hamlin left the House in 1841. He served two terms in the United States House of Representatives, from 1843-1847. He was elected to fill a Senate vacancy in 1848 and to a full term in 1851. A Democrat at the beginning of his career, Hamlin supported the candidacy of Franklin Pierce in 1852.
From the very beginning of his service in Congress he was prominent as an opponent of the extension of slavery; he was a conspicuous supporter of the Wilmot Proviso, and spoke against the Compromise Measures of 1850. In 1854 he strongly opposed the passage of the Kansas-Nebraska Bill, which repealed the Missouri Compromise. After the Democratic Party endorsed that repeal at the Cincinnati Convention two years later, on June 12, 1856 he withdrew from the Democratic Party and joined the newly organized Republican Party, causing a national sensation.
The Republicans nominated him for Governor of Maine in the same year, and having carried the election by a large majority he was inaugurated in this office on the January 8, 1857. In the latter part of February, however, he resigned the governorship, and was again a member of the Senate from 1857 to January 1861.
He was chosen for the second place on the winning Republican ticket in 1860. While Vice President he was one of the chief advisers to President Abraham Lincoln, and urged both the Emancipation Proclamation and the arming of African Americans. His identification with the Radical Republicans caused him to be dropped from the ticket in 1864 in favor of Andrew Johnson, who was a member of the Democratic Party and a southerner.
Hamlin served in the Senate from 1869 to 1881. His last post was minister to Spain, from 1881 to 1882.
He died in Bangor, Maine, on July 4, 1891 and is buried in Mount Hope Cemetery.
He had two sons, Charles Hamlin and Cyrus Hamlin, who served in the Union forces during the Civil War. Charles and sister Sarah were present at Ford's Theater the night of Lincoln's assassination. His son Hannibal Emery Hamlin was Maine state Attorney General from 1905 to 1908.
There are biographies by his grandson Charles E. Hamlin (published 1899, reprinted 1971) and by H. Draper Hunt (published 1969).
Hamlin County, South Dakota is named in his honor.