You are really, truly stupid. The Iranian people have not been freed in any way, they are still subject to an oppressive government AND they are having their electricity and water cut off by attacks by the US and Israel.
Most of the slaves were not overjoyed at all, as the Civil War did not grant them land to farm, and that was the only trade they knew. There are hundreds of books written about the confusion caused by the destruction of the plantations. What happened in 1866 and 1867 was a lot of starvation of both the Black and White populations.
The luckiest ones were those that were protected by the Freedman's Bureau and the Union Army.
There was a short period from 1867 and 1877 when Black people were allowed to vote and elected Black representatives and senators. Then the Republicans sold them out so that Hayes, who got fewer votes became president in exchange for withdrawing the Union Army and the Freedman's Bureau.
That was when your racist ancestors took over and imposed Jim Crow laws.