“The people of Texas are informed that in accordance with a Proclamation from the Executive of the United States, all slaves are free. This involves an absolute equality of rights and rights of property between former masters and slaves, and the connection heretofore existing between them became that between employer and free laborer.”
—General Order 3
The Civil War was beginning to mount enormous casualties, and Lincoln felt it necessary to use the victory at Antietam to further push the war in the Union’s favor. Just five days after the Union’s victory, Lincoln announced an ultimatum for the institution of slavery with the Preliminary Emancipation Proclamation. This order declared that the rebel southern states had by January 1, 1863, to rejoin the Union or their slaves shall be, “then, thenceforward, and forever free.” Lincoln’s order, while it did not free anyone immediately, had the effect of turning the war into a struggle for emancipation threatening the centuries-old institution serving as the cultural and economic epicenter of the South.
 Abraham Lincoln. Preliminary Emancipation Proclamation. Washington, D.C. September 22, 1862. (Accessed January 31, 2018.) https://www.archives.gov/exhibits/american_originals_iv/sections/preliminary_emancipation_proclamation.html#