Why did the second Battle of bull run take place?
It was another battle during the civil war, and battles happen for defense and offense of the land. The South fought an defensive war (besides Gettysburg), and the Union was figthing to preserve itself, not only against slavery. It was a battle that occured in the South (the only northern battle was in Gettysburg, Pennsylvania), and the Northy was trying to weaken the south. Most thought that the war was going ot take less than a year, and the North was trying ot meet that goal while trying ot preserve the Unioin as a whole.
