noun The act of setting free from the power of another, as from slavery, subjection, dependence, or controlling influence.
noun The state of being thus set free; liberation (used, for example, of slaves from bondage, of a person from prejudices, of the mind from superstition, of a nation from tyranny or subjugation).
US President Abraham Lincoln was called the Great Emancipator after issuing the Emancipation Proclamation in 1863.