Spain and the American Civil War

During the American Civil War, the Kingdom of Spain was the target of intense diplomatic efforts by representatives of the United States and the Confederate States of America. At the start of the war, both sides believed that Spain was the likeliest European country to recognize the Confederacy, due to having poor relations with the United States long before Secession, and the persistence of slavery in Spanish Cuba and Puerto Rico.

Source: Wikipedia — Spain and the American Civil War (CC BY-SA 4.0)