Simon Cameron (March 8, 1799 – June 26, 1889) was an American politician who served as United States Secretary of War for Abraham Lincoln at the start of the American Civil War. Cameron made his fortune in railways, canals and banking, founding the Bank of Middletown. He then turned to a life of politics. He became a U.S. senator in 1845 for the state of Pennsylvania, succeeding James Buchanan.