Why didn’t lincoln free all the slaves in the united states?

Okay, so, Lincoln had to wait for a Union victory. Antietam Was the victory he needed.

The Emancipation Proclamation changed the course of the war. It went from defeating the Rebels of the South to freeing the slaves. In every place that the Union army could take, the Slaves were all freed. This was a huge boost to the troops. They were now fighting to free people. Freeing all the slaves would have done nothing to keep the men fighting. the fight needed a better cause. Is there a better cause than Freedom? Fighting to unite the Country and fighting for freedom are far different things. Even today fighting for freedom is still top on everyones list.
I hope this helped you. :)

Lincoln did believe that slavery was morally wrong, but there was one big problem: It was sanctioned by the highest law in the land. the Constitution. The nation's founding fathers, who also struggled with how to address slavery, did not explicitly write the word "slavery" in the Constitution, but they did include key clauses protecting the institution, including a fugitive slave clause and the three-fifths clause, which allowed Southern states to count slaves for the purposes of representation in the federal government. In a three-hour speech in Peoria, Illinois, in the fall of 1854, Lincoln presented more clearly than ever his moral, legal and economic opposition to slavery--and then admitted he didn't know exactly what should be done about it within the current political system.