With everything going on in the USA today, I'm wondering if the world (or, more precisely, Europe) was somehow a part of the American civil war of 1861
This answer about Russia and this about Latin America should be of interest, as well as this one on reactions to Lincoln's death.
Here are two threads related to your question, with very good answers by u/mormengil . No European power directly intervened in the war. Although some European countries had economic relations with the Confederacy (buying cotton, selling weapons), their governments were reluctant to get involved because of the South’s support for slavery, among other factors.