After the war, he became the first African
American to serve

Hiram Rhodes Revels

Explanation:

Born free in North Carolina, he later lived and worked in Ohio, where he voted before the Civil War. He became the first African American to serve in the U.S. Congress when he was elected to the United States Senate as a Republican to represent Mississippi in 1870 and 1871 during the Reconstruction era

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because mexico wanted to choose a centralized location

thurgood marshall

explanation: in 1954, thurgood marshall and a team of naacp attorneys won brown v. board of education of topeka, kansas. in this landmark decision, the supreme court held that segregation in public education violated the equal protection clause of the fourteenth amendment.