In the 248-year history of the United States, only one president has managed to return to the White House after losing an election: Democrat Grover Cleveland in 1892.
Cleveland entered politics in Buffalo, New York in the 1880s with an anti-corruption message and became President of the United States in 1884. He lost the election of 1888, but returned to the White House after winning the presidential election of 1892. Cleveland was the first Democratic president elected after the end of the American Civil War in 1865. He is also the only president to have married while in office.
Donald Trump is now only the second president to make a similar return to the White House.