June 19, 1865, is when the slaves in Galveston learned that they were free because the war was over. Black people elsewhere in Texas who were being held as slaves would not have heard the news until later, and slavery was still legal in Kentucky and other slave states which had not seceded until Dec. 6, 1865 (although in practice it may have been hard to force anyone to work as a slave during the months before ratification was completed).
Techenacly, the date should be Dec. 6th.