Answer;
-They wanted to make the announcement following a union victory.
Explanation;
-The members of Lincoln's cabinet urged him to wait before announcing the emancipation of southern slaves because they wanted to make announcement following a union victory.
-The Emancipation Proclamation granted freedom to the slaves in the Confederate States if the States did not return to the Union by January 1, 1863. Also under this proclamation, freedom would only come to the slaves if the Union won the war.