Why was atlanta significant to the union and whose leadership led to its seizure by the union?

Union forces commanded by William T. Sherman, wanting to neutralize the important rail and supply hub, defeated Confederate forces defending the city under John B. Hood. After ordering the evacuation of the city, Sherman burned most of the buildings in the city, military or not. After taking the city, Sherman headed south toward Savannah, beginning his Sherman’s March To The Sea.

African americans at the time just came out of slavery and needed money to provide for there families. so they joined for the money mainly.