The Commonwealth of Virginia was a prominent part of the Confederate States during the American Civil War. As a slave-holding state, it held a state convention to deal with the secession crisis, and voted against secession on 4 April 1861. Opinion shifted after 15 April, when U.S. President Abraham Lincoln called for troops from all states still in the Union to put down the rebellion, following the capture of Fort Sumter, and the Virginia convention voted to declare secession from the Union. (In the Western counties, where there was little slavery, pro-Union sentiment remained strong, and they presently seceded from Virginia as a separate Union state, West Virginia.)