What is the cause the the First Battle of Bull Run?

Answer 1

The cause is to the Battle of

Bull Run is because the Bob became so violent, all the states wanted to seced.

Answer 2

The cause of the First Battle of Bull Run, also known as the First Battle of Manassas, was the escalating tensions between the Northern and Southern states leading up to the American Civil War. It was begun when Union forces, under General Irvin McDowell, launched an offensive against Confederate troops, under General P.G.T. Beauregard, near Manassas, Virginia on July 21, 1861. The battle was primarily fought to assert control over the strategically important railroad junction at Manassas, but it ultimately resulted in a Confederate victory.