Williams was born on December 22, 1898, in Bennettsville, South Carolina, as the last of five children; his father was a former slave, while his mother was a cook, nurse, and evangelist. His innate curiosity concerning the realities of racial inequality and cultural struggles, particularly those which involved African Americans, began as early as his fifth-grade year. Years later, he was quoted in an early interview as saying: "I was very sensitive about the position of Black people in the town... I wanted to know how you explain this great difference. How is it that we were in such low circumstances as compared to the whites? And when they answered 'slavery' as the explanation, then I wanted to know where we came from."

He moved with his family to Washington, DC in the early 1900s. His first wife, Dorothy Ann Williams, died in 1925, leaving him a widower with five children.

Williams earned an undergraduate degree in Education in 1930 followed by a Master of Arts degree in History in 1935, both from Howard University. After completing a doctoral dissertation on the socioeconomic significance of the storefront church movement in the United States since 1920, he was awarded a Ph.D. in history and sociology by American University in 1949.

Williams began his studies abroad as a visiting professor to the universities of Oxford and London in England, UK in 1953 and 1954. In 1956, he did field research in African history at Ghana's University College. At that time, his main focus was on African achievements and self-ruling civilizations which existed long before the coming of the Europeans or Asians. His last study, completed in 1964, covered 26 countries and more than 100 language groupings.

In 1935 Dr. Williams took the post of Administrative Principal for the Cheltenham School for Boys in Maryland. Four years later he became a teacher in the Washington, DC public schools. He entered the employment of the U.S. Federal Government in 1941, filling a variety of positions such as section chief of Census Bureau, statistician for War Relocation Board, and economist in Office of Price Administration. In 1946 he returned to his alma mater as a social science instructor until 1952. It was then that he transferred to the history department, where he remained until he retired in 1966.

In 1971, Williams sent his magnum opus The Destruction of Black Civilization to Kendall Hunt, a white-owned publishing company, for publication and distribution. The following year, the book received an award from the Black Academy of Letters and Arts. Encouraged by the award, Williams worked for years to expand and revise the book before publishing a second edition. Feeling more comfortable with a Black-owned firm as his publisher, he sent the second version to Chicago's noted Third World Press.

When published in 1987, the second edition of the book received a wide wave of critical acclaim, including from such people as New Jersey poet laureate Amiri Baraka and noted professor John Henrik Clarke. Years of cultural change enabled people to see the value of Williams' work. The 21st Century Foundation honored Chancellor Williams, making him the first person to receive its Clarence L. Holte International Biennial Prize.

Preparing to release his most famous book, Williams did not wait for grants or fellowships to publish it. On his apparent hastiness, he commented: "I was out of step with tradition." He also said, "I rebelled against overspecialization. Even when I had the required courses for my majors, I would take other subjects in which I was equally interested. I was interested in pure science, for example, even though I was majoring in history. I was also interested in psychology. My transcripts from Howard, where I did most of my formal study, won't give you any idea of what my major really was."

Dr. Williams died of respiratory failure on December 7, 1992 at Providence Hospital. He had been a resident of the Washington Center for Aging Services for several years. He was survived by his wife of 65 years, Mattie Williams of Washington, and 14 children; 36 grandchildren; 38 great-grandchildren; and 10 great-great-grandchildren.