On November 29, 1864, the International Workingmen's Association, a federation of European workers, trade unionists, and social reformers founded in London, wrote to Abraham Lincoln. “We congratulate the American people upon your reelection by a large majority,” the address began, drawing attention to the importance of the popular vote in sounding the death knell to slavery in the American republic. “If resistance to the Slave Power was the reserved watchword of your first election, the triumphant war cry of your reelection is, Death to Slavery.” Written in English by Karl Marx and signed in London on behalf of the International Workingmen's Association by some fifty-seven members from Great Britain, France, Italy, Poland, and Switzerland, the letter envisions the Civil War not as an isolated national or internecine struggle but in epic terms as a “titanic American strife” in which “the star-spangled banner” will also determine “the destiny” of European workers.

Lincoln's speeches had consistently envisioned the Union war as part of a world historical struggle for the people and democracy: “We cannot escape history,” he said of the logic of emancipation in an address to Congress in 1862, “We know how to save the Union. The world knows we know how to save it.” The International Workingmen viewed the American Civil War in similarly historical and global terms. However, for them it was a war for black and white free labor.