Why did West Virginia leave Virginia?

As the Civil War approached, Virginia was considered a border state. It had voted three times NOT to secede. After South Carolina fired on Ft. Sumter on April 12, 1861, President Lincoln called for 75,000 volunteers to put down the rebellion in the South. Not wanting to be part of an invasion of the South, Virginia had another secession vote, and this time voted to secede. Only Alexandria, just south of the Potomac River from Washington, DC, and the Western counties of Virginia, cast their votes against secession. Lincoln created a second, shadow government of Virginia (the real one was no longer part of the Union). Once there was an agreeable Union government, the western part of Virginia voted to secede from Virginia and call itself "West" Virginia. It became a new state on June 20, 1863.