Which two developments gave black American men the opportunity to participate in state governance in spite of racial discrimination?

the abolition of slavery and the sharecropping system.

Although there were several events that gave participation to black people in the governments, these were the most important:

The Civil Rights Movement in the United States: it was a long, and mainly non-violent, struggle to extend full access to civil rights and equality before the law to groups that do not have them, especially black citizens. Little Rock, 1957: Also known as Little Rock Crisis was a key moment in American civil rights movements, following the decision of the Supreme Court in the Brown case, the school committee of Little Rock, Arkansas, voted in 1957 to integrate the school system.