Why did Lincoln allow states to return to the US before he emancipated the slave?

Lincoln allowed states to return to the Union before emancipating the slaves primarily to promote reconciliation and restore the Union as quickly as possible. He believed that re-establishing loyalty and governance in the Southern states would help stabilize the nation. Additionally, he aimed to encourage Southern states to rejoin the Union by offering a path to readmission without the immediate pressure of abolition, hoping to gradually shift attitudes towards slavery. The Emancipation Proclamation came later as a strategic wartime measure, shifting the focus to ending slavery as a means to weaken the Confederacy.