The First Battle Of Bull Run On July 21, 1861, two armies, one confederate and the other Union, prepared for the first major land battle of the Civil War. In 1861 Abraham Lincoln was sworn in as President. The Southern states had seceded and the South had fired on and captured Fort Sumter on April 12 1861. After the Fort Sumter battle, both the North and the South began preparing for war by raising armies. This was done quickly and neither side spent much time training the troops. Both sides also did not know what a long and terrible war was ahead. The first Battle of Bull Run took place near Manassas Junction, Virginia, an important railroad junction twenty five