Why was the emancipation proclamation made?

Freedom for slaves

It was an attempt to free the slaves in the Southern states because the North found slavery unconstitutional.

The Emancipation Proclamation was announced for several reasons, which can be simplified into 2 parts:

1) Raise morale for Union troops and give them another reason to fight besides re-uniting the nation, as the series of defeats due to Union commanding officers' incompetence and Confederate General Robert E. Lee tactical brilliance.

2) Encourage international support to tip in the Union's favor as they added the reason of ridding slavery as a goal of the war. (Almost all countries of the "civilized " world had rid themselves of slavery)