You know better than that, Di.
When the war ended, there were only two states where slavery remained legal. DE and KY. Slave in all other states had already been freed either by the Emancipation Proclamation or by state action.
Maryland ended slavery November 1, 1864. That is most of the way through the war.
Missouri ended slavery January 11, 1865, which is also most of the way through the war.
They certainly didn't end slavery on April 12, 1861.
Your quibble is over matters of months.