Abraham Lincoln actually said...
on the 1st day of January, A. D. 1863, all persons held as slaves within any State the people whereof shall then be in rebellion against the United States shall be then, thenceforward, and forever free
Context
Proclamation 93—Declaring the Objectives of the War Including Emancipation of Slaves in Rebellious States on January 1, 1863
09/21/1862