<P> The American Civil War was fought in the United States from 1861 to 1865 . The result of a long - standing controversy over slavery , war broke out in April 1861 , when Confederates attacked Fort Sumter in South Carolina , shortly after 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>
civil war what did the north fight for
loyalty to the U.S. Constitution