What historical influences evolve jazz?

Slavery helped evolve jazz when slaves sang the blues , they often sang about suffering and reminiscing over death.

The region of the united states where beef and hog production is prevalent is the midwestthere are 12 states in this area including  illinois,  indiana,  iowa,  kansas,  michigan,  minnesota,  missouri,nebraska,  north dakota,  ohio,  south dakota, and  wisconsin. all of these states are known for their meat and such products. 

Just pretend that your talking to a empty room