You can read the entire passage for your own edification. These specific elements caught my attention:
As one of only two black Congressmen, Powell challenged the informal ban on black representatives using Capitol facilities reserved for white members only. He took black constituents to dine with him in the "whites only" House restaurant. He clashed with the many segregationists in his own party.
In 1956 Powell broke party ranks and supported Dwight D. Eisenhower for reelection, saying that the Democratic platform's civil rights plank was too weak.
In 1958 he survived a determined effort by the Tammany Hall machine to oust him in the Democratic primary election.
In 1960, Powell forced Bayard Rustin to resign from the Southern Christian Leadership Conference (SCLC) by threatening to discuss Rustin's "immoral" homosexuality in Congress. He was concerned that questions about Rustin adversely affected the reputation and effectiveness of the SCLC.
He passed legislation that made lynching a federal crime, as well as bills that desegregated public schools and the U.S. military. He challenged the Southern practice of charging Blacks a poll tax to vote, and stopped racist congressmen from saying the word "nigger" in sessions of Congress.
Powell sued in Powell v. McCormack to retain his seat. In June 1969 the Supreme Court ruled that the House had acted unconstitutionally when it excluded Powell, a duly elected member. He returned to the House, but without his seniority. Again his absenteeism was increasingly noted.
In June 1970 Powell was defeated in the Democratic primary by Charles B. Rangel. In fall 1970, Powell failed to get on the ballot for the November election as an Independent. He resigned as minister at the Abyssinian Baptist Church and moved to Bimini. Rangel has continued to represent the district, as of 2009.