Conversation so far:
which side was maryland on in the civil war
During the months leading up to the Civil War, Maryland stood as a house divided. Although it was a slaveholding state, Maryland did not secede.
when was the first blood of the american civil war shed
On April 19, 1861, a secessionist mob in Baltimore attacks Massachusetts troops bound for Washington, D.C. Four soldiers and 12 rioters were killed.

Question: when was the executive order issued
Self-contained rewrite: when was the preliminary emancipation proclamation issued