First, referring to Lincoln as a "cockroach" only illuminates your odium of him and his program, and it doesn't do anything to persuade anyone that Lincoln was wrong in what he did, but only that you are very hostile to him, which makes it harder to accept your arguments -- in just the same way that John Nicolay's partisanship makes it harder to trust or accept his "history" of the beginnings of the Civil War, or his recounting of the issues that launched it. There is such a thing as being too angry to argue about something.
While I think Karl Marx may have been correct in his surmise of Lincoln as "‘the single-minded son of the working class’ who led his ‘country through the matchless struggle for the rescue of an enchained race and the reconstruction of a social world.’", in your quotation of McPherson's quotation of Marx, nevertheless that doesn't establish that Lincoln was in fact a Socialist, much less a Marxian one. In fact, the numerous litmus tests used by Lenin to subdivide and "purify" (if that's the word) the doctrinal program and cadres of the Russian Communist Party tend to weigh against your assertion: only three points of convergence? Hardly enough to satisfy a real 20th-century Marxist.
Furthermore, some of the points of convergence are at least as Whiggish as they are Socialist, particularly the railroad infrastructure scheme, which echoes the Erie Canal, and the idea of establishing land-grant colleges (at one of which I was educated: truth in advocacy). The latter would not, I think, be recognized by anyone studying Marxism in the 20th century as a peculiarly Marxist position, because which came first? The Whiggishness of the land-grant idea, or its embrace by Socialists? I don't know; you tell me. I suspect the former.
I would tend to regard the presence of failed revolutionaries of 1848 in the Union army as a demographic accident; given that these men might have had to flee before their victorious adversaries, where should they have gone, that gave them a semblance of Europe, but without the secret policemen? I shouldn't be surprised to find such men in Australia and South America as well. A fair assessment of whether Lincoln's cause was a particular magnet for these men would have to review both the distribution of '48 revolutionaries in the aftermath, and the correspondence of the Union Generals like Schurz and Sigel themselves. Otherwise, all we have is a demographic fact of life.
I've heard the assertion about Joshua Speed before, and I don't know what to make of it; it could easily be a mischaracterization. Burlingame's book sounds like the kind one reads after 1 a.m., after everyone else has gone to sleep; I would want someone else to tell me whether Burlingame is "for real" before I would touch his book with a ten-foot pole, frankly. I would also tend to regard Lowry's book the same way, as a titillating sort of work, unless of course he Lowry turns out to be a credentialed researcher. I would want to know a lot more about both authors before cracking their books. The main trouble with assertions like theirs is that they constitute an extended ad hominem argument about Lincoln, until and unless someone can credibly show how his policies arose from some psychosexual well of discontent. I should be skeptical of such an argument anyway, but since Garry Wills shrank Richard Nixon to loud applause in Nixon Agonistes, I have been game to see sauce for the goose applied to the gander as well.
As for the Sandburg quote, are you saying, or is someone saying, that Sandburg is writing proto-gay code?
On the whole, stripping the marble off public figures is a necessary exercise for the student who wants to learn more than the accepted public pieties. Such efforts at revision are now underway for Robert E. Lee and Franklin Roosevelt as well, and I hope we all learn something from them. However, nobody benefits if the object of the exercise is just to throw mud. It may be true, but it also needs to be germane to hold our attention.
Well said!
Richard F.