There are many answers to this question. The first thing to understand this was an era spanning from the 1890s to the end of WWI. Black Americans were trying to leave the south because of the Jim Crow laws and unfair voting circumstances happing in southern states. Soon after the Emancipation Proclamation of 1863, we see mass outrage. The first KKK was funded. To flee the angry South, black Americans tried to find work in factories in the north. Many believed that going north would solve their problems. Many black men enlisted in WWI in hopes of a guaranteed job, but soon found out the military was segregated and they revived lower wages.