 Under President Johnson, Williams became the first black representative to the United Nations Economic and Social Council and later was appointed Ambassador to Ghana.During his three-year tenure at this post, he was credited with improving the formerly strained relations between the United States and the African nation.Leaving government service in 1968 Mr. Williams headed the Columbia University Urban Center, issuing the study "Human Uses of the University - Planning a curriculum for Urban and Ethnic Affairs at Columbia University."