Black was known throughout the South for his activism in the Civil Rights Movement. Throughout the late 1950s and 1960s, he along with State Representative G. J. Sutton and Harry Burns led and organized marches throughout the state. He challenged former Texas Governor Price Daniel, former San Antonio Mayor Walter McAllister and the establishment for their unfair treatment of minorities in the city. While addressing a city council meeting in 1952, he was ignored and called a ------ on the open microphone. He became an associate of such leaders as A. Philip Randolph, Martin Luther King, Thurgood Marshall, Adam Clayton Powell, Jr. , James L. Farmer, Jr. Ella Baker and others. As a local ally to President Lyndon B. Johnson, Black was present for the White House Conference on Civil Rights in 1966. He endured many threats to himself, his family and even his church. A drive-by shooting occurred at his home as well as his church burned in 1974 with no suspects being charged. Black supported the efforts of San Antonio SNCC, after a massive demonstration against police brutality in downtown San Antonio and an armed attack on the SNCC office. He allowed use of the church for meetings of the San Antonio Committee to Free Angela Davis, SNCC-Panther meetings, and allowed members of the SNCC-Panthers opportunities to raise funds at the church on Sunday. Rev. Black co-authored a city council resolution against the sale of the South African Krugerrand Gold Coin, in December 1976, before Nelson Mandela was released from prison.