Apparently Louis isn’t familiar with Karl Marx’s enthusiasm for Abe Lincoln and the Radical Republicans.
Marx closely followed the American Civil War as a correspondent for Horace Greeley’s New York Tribune. And as the secretary for the First International he drafted their letter of support to Lincoln.
Marxists, including the original one, saw Lincoln as being ‘on the right side of history’ unlike the hated reactionaries of the Old South. A number of Marx’s exiled ‘48er comrades were involved in the founding of the Republican Party and even held government and army positions.
https://www.jacobinmag.com/2012/08/lincoln-and-marx
...Marx, in a leaflet supporting Polish independence, contrasted the German bourgeois liberals’ betrayal of Poland with the English workers’ support of the Northern war effort. Marx proclaimed: “The English working class has won immortal historical honor for itself by thwarting the repeated attempts of the ruling classes to intervene on behalf of the American slaveholders by its enthusiastic mass meetings, even though the prolongation of the American Civil War subjects a million English workers to the most fearful suffering and privations.”
Unfortunately, Marx’s career with the Republican Party was cut short by another economist, who might also claim some credit as the first environmental economist. Henry Charles Carey was the son of Matthew Carey, a rather anti-British bookseller and printer until his criticism of the government made him flee to Paris to avoid prosecution in England. There he met Benjamin Franklin and the Marquis De Lafayette, who gave him $400 to begin a new publishing company after he arrived in the United States. Matthew Carey was the first American political economist and the first major publisher in the country.
https://www.counterpunch.org/2015/12/25/how-karl-marx-helped-shape-the-republican-party/
Lincoln, for his part, steered his own ship, notwithstanding the blandishments of European intellectuals.