In 1952 he helped found "Americans for South African Resistance" (AFSAR) to organize support in the U.S. for the ANC-led Defiance Campaign against apartheid in South Africa. He was a founder in 1953 of the American Committee on Africa (ACOA), which grew out of AFSAR. In 1954 he took his first trip to Africa, visiting West Africa and South Africa. In 1960, as president of ACOA, Houser sent a telegram to Dwight Eisenhower urging him to officially condemn the treatment of Africans by South Africa. Because of his continuing activities for independence and against apartheid, Houser was not permitted to enter South Africa again until 1991, after the end of the apartheid government.