Indeed, and one of the key elements being considered for the story is how people from our time have to deal with what is, for the vast majority of them, a stunning/despicable level of casual/open racism in all of America, not just the South, and how Lincoln in ATL 1861-62 wouldn't be as strong on or have evolved to the stances on emancipation and black civil rights that he did from OTL 1863 onward. They might stomach no slavery beyond current borders, and plans for gradual compensated emancipation, with private/semi-public options created for black education, landholding, equal wages, etc., in the event of an early Northern victory. However, there would certainly be some from our time who'd want to push for immediate freedom, equality and all other rights that (in law if not always in reality) are the norm in our time, something which the bulk of 19th century American whites, North and South, would never accept. Makes for interesting tensions/pressure, as you say, and the possibility of a break between Lincoln and the time-travelers...which, in turn, lets the real threats, from our time and this ATL, operate with less chance of discovery.