Slavery was officially abolished in the United States in 1865 (by the enactment of the 13th Amendment to the Constitution), although many states abolished slavery for themselves at various dates between 1777 and 1864 and the transport of new slaves from Africa to the US was stopped as early as 1808.lavery was officially abolished in the United States in 1865 (by the enactment of the 13th Amendment to the Constitution), although many states abolished slavery for themselves at various dates between 1777 and 1864 and the transport of new slaves from Africa to the US was stopped as early as 1808.