The consensus belief when Lincoln was a young man was that the country wouldn't be able to get rid of slavery without resettling the freed slaves in Africa or elsewhere outside the US. Lincoln went along with that belief, as did other Americans who had moral qualms about slavery. By 1865, he realized that African-Americans didn't want to be resettled. He also believed that those who were educated or who had fought in the war had earned the right to be citizens and vote. Resettlement efforts during the war had largely failed. It was also generally realized by 1865 that the South (and the country) wasn't going to get back on its feet without some Black participation in the labor force. Lincoln might favor continued attempts at voluntary resettlement of freedmen as a way of lessening the "racial problem," but he didn't favor involuntary deportations. Anyway, given what racial attitudes were in the 19th century, it isn't surprising that Americans who didn't like slavery were also in favor of resettlement efforts.
JFK wanted to get us out of Viet Nam after he got reelected. True?
My understanding was that he wanted some kind of a change. The bigger question is whether it would have lasted, or whether he'd put the troops he'd take out back in under another label. I don't think anybody can say for certain that Kennedy wanted to bring our involvement in Vietnam to a definitive and final end. Diem had just been overthrown. Kennedy approved (though maybe not of Diem's murder). Kennedy thought that might solve some problems and some US troops could be pulled out. Would he put them back in when it turned out that the coup had solved nothing? I think so.
It feels as though you are trying to sanitize his views on the matter. Lincoln spoke them plainly.
"Why should they leave this country? This is, perhaps, the first question for proper consideration. You and we are different races. We have between us a broader difference than exists between almost any other two races. Whether it is right or wrong I need not discuss, but this physical difference is a great disadvantage to us both, as I think your race suffer very greatly, many of them by living among us, while ours suffer from your presence. In a word we suffer on each side. If this is admitted, it affords a reason at least why we should be separated."