Marx and Lincoln corresponded to the end of the American Civil War. Although separated more things than the Atlantic, agreed on the cause of free workers and the urgent need to end slavery. These writings point to the important role of international communists in opposition to European recognition of the Confederacy. Opposite the London presumptuous liberal view of his time , who claimed that the real reason for the conflict were tariffs, Marx knew that the crisis had to do with slavery . He was aware that capitalism could easily support it and even prosper from this and other forms of human bondage. His numerous writings on the Civil War , far from advocating socialism white, show a universalist intention " only breed rescue chained lead to the reconstruction of a social world."

Soon after, the ideals of communism attracted thousands of followers throughout the U.S., and the International Workers Association tried to radicalize Lincoln 's unfinished revolution promoting the rights of blacks, whites and native and foreign workers , contributing to a thorough review of the magnates who were enriched by the war, and inspiring an extraordinary series of strikes and class struggles in the following decades.