I believe "gradualism" was dead by the end of the 1840's. The "immediatists" and "radical abolitionists" were in control of the abolitionist movement and had adopted the "John Brown" view of emancipation, if necessary.
Communications within Lincoln's cabinet and among his advisers, clearly eliminates the possibility of negotiation or any other policy, which would consider compensation or gradualism. The radical abolitionists would have bolted from the Republican party and it would have died in its infancy or, at least, Lincoln thought so.
Why did the Federal government never attempt to implement any programs after emancipation to rehabilitate former slaves. Apathy?