Hannibal Hamlin, American lawyer and politician, 15th Vice President of the United States (born 1809)

Hannibal Hamlin was an American politician and diplomat who was the 15th vice president of the United States, serving from 1861 to 1865, during President Abraham Lincoln's first term. He was the first Republican vice president.

The vice president of the United States is the second-highest ranking office in the executive branch of the U.S. federal government, after the president of the United States, and ranks first in the presidential line of succession. The vice president is also an officer in the legislative branch, as the president of the Senate. In this capacity, the vice president is empowered to preside over the United States Senate, but may not vote except to cast a tie-breaking vote. The vice president is indirectly elected at the same time as the president to a four-year term of office by the people of the United States through the Electoral College, but the electoral votes are cast separately for these two offices. Following the passage in 1967 of the Twenty-fifth Amendment to the US Constitution, a vacancy in the office of vice president may be filled by presidential nomination and confirmation by a majority vote in both houses of Congress.