Born in 1858, Williams was the son of a barber who was African-American and Scots-Irish and considered a "free negro", and an African-American mother. The family moved to Baltimore from Pennsylvania when Williams' father died when Williams was nine-years-old. In the following years, he studied to become a barber like his father and relocated to Wisconsin. It was there he began his serious course of studies that led him to become a physician.
In 1883, Williams graduted with his MD degree and went on to practice in Chicago, where he was one of only three practicing doctors of African-American descent. It was in 1893, that Williams performed a new type of surgery on a young man with stab wounds to his chest to repair a tear in the heart lining, saving the young man's life.
Williams who saw the need for a place to train nurses and interns of African-American descent founded Provident Hospital in 1896.
Williams married Alice Johnson, in 1898. Williams continued in private practice for many years and would go on to serve on several boards, teach at the university level, and became a leader who encouraged the development of more hospitals where African-Americans could receive health care and health care providers could receive training.
At his death in 1931, Williams was hailed as "a medical missionary [and] a veritable Moses to the
Negro profession." He is also famously mentioned in Stevie Wonder's "Black Man" on Wonder's Songs in the Key of Life album.