not sure how much any of this really matters, and i really don't mean to come across as a jerk here, but i've read just about everything that marx wrote about the u.s., i'm looking at collection of his stuff on the u.s. that i just pulled from book shelf...
marx wrote 6 articles about the civil war for the _new york daily tribune_ prior to the newspaper ending its decade-long relationship with him (*see comment below about this*), during this same time, marx wrote 35 articles about the civil war for the vienna newspaper _die presse_ (2 of which engel co-authored, the latter of which you posted excerpt from yesterday)...
km's daughter eleanor wrote after his death that her father thought lincoln a fighter for freedom, but that marx considered him to be rather bumbling and bungling, only a child during the civil war, adult-age eleanor indicates that she became obssessed with the union winning and says that she would write letters to lincoln giving him advice, she was apparently led to believe that her father posted the letter but, in fact, he kept them in a safe place and showed them to her years later (i have to admit that i like idea of young eleanor marx advising lincoln)...
i'll withdraw comment about 'half-baked' as it seems to have irritated you, however, i'll stick with point that i intended to make - there is no credible evidence for claim linking marx/engels & lincoln/union commanders... mh
*marx's relationship with the tribune was difficult, newspaper paid by the piece and only when the piece ran under a writer's by-line, so km didn't get paid for unprinted articles, moreover, the paper sometimes published his articles either as unsigned editorials or as "from our foreign correspondent" for which he recived smaller payment...
marx was only foreign journalist that trib maintained after southern states seceded in 1861, however, it published none of his submissions for the remainder of that year, it printed 8 in early 1862, his final article warning against intervention of european powers in mexico during u.s. civil war...*