Attempts? To whom are you referring? My comment was addressed at the false contention that Abe freed slaves outside the occupied areas of the Confederacy nothing else.
If by "free", you mean that this group was excluded from the Emancipation Proclamation and the federal orders pursuant to that document.
Lincoln, along with Attorney General Bates and other members of the cabinet did attempt-with partial success-at enacting a policy of compensated manumission during the war years, post-1862.