Question

president lincoln issued the emancipation proclamation after
o the unions effectiveness at the battle of antietam.
o the death of general jackson at chancellorsville.
o the nation had voted to decide the issue of slavery.
o the capture of washington, dc, by confederate forces.

Explanation:

The Emancipation Proclamation was issued by President Lincoln after the Union's success at the Battle of Antietam. This battle was a significant turning - point in the Civil War, providing Lincoln with the military victory he felt was necessary to issue such a proclamation. General Jackson died at Chancellorsville after the Emancipation Proclamation was issued. Slavery was not decided by a national vote, and Washington, DC was not captured by Confederate forces.

Answer:

the Union's effectiveness at the Battle of Antietam.