ProgressingAmerica: "Thomas Jefferson was an abolitionist."DiogenesLamp: "In theory. In practice, he was not."
Certainly, by 1860 standards, Jefferson was a radical abolitionist because he:
Like nearly all of our Founders, Jefferson considered slavery a necessary evil which should be eventually abolished -- gradually, peacefully and with compensation for slaveholders.
That idea was still very much alive when Jefferson died in 1825, but within just a few years after -- by the 1830s -- had been entirely abandoned by most Southerners.
His son, James Lemen Jr., did know Abraham Lincoln. Article here.