<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The American Civil War (also known by other names) was a war fought in the United States from 1861 to 1865 . As a result of the long - standing controversy over slavery, war broke out in April 1861, when Confederate forces attacked Fort Sumter in South Carolina, shortly after U.S. President Abraham Lincoln was inaugurated . The nationalists of the Union proclaimed loyalty to the U.S. Constitution . They faced secessionists of the Confederate States, who advocated for states' rights to expand slavery . </P> <P> Among the 34 U.S. states in February 1861, seven Southern slave states individually declared their secession from the U.S. to form the Confederate States of America, or the South . The Confederacy grew to include eleven slave states . The Confederacy was never diplomatically recognized by the United States government, nor was it recognized by any foreign country (although the United Kingdom and France granted it belligerent status). The states that remained loyal to the U.S. (including the border states where slavery was legal) were known as the Union or the North . </P>

President of the united states during the civil war