William Knox Flowers, Sr., was an African-American physician born in Raleigh, Mississippi, on July 8, 1886. He was the son of Jordan and Mary Flowers. The death of his sister motivated him to pursue a medical degree. He attended Meharry Medical College in Nashville, Tennessee, after graduating from Alcorn A&M College in Mississippi. He graduated from Meharry in 1913 and left for Chicago to engage in postgraduate work.
After completing his studies, Flowers eventually traveled to Terrell, Texas, where he met Lee G. Pinkston, a prominent black surgeon in Dallas and founder of the Pinkston Clinic Hospital. Pinkston encouraged Flowers to move to Sulphur Springs to begin his medical practice. In 1918 while he was practicing medicine in Sulphur Springs, an influenza epidemic broke out and became widespread. Hoping to find a remedy for this illness, Flowers proceeded to develop a treatment for black patients; because other physicians were unsuccessful in their attempts to treat the disease, they referred their patients to Flowers.
Flowers and Bonnie Pearl Perry married in 1916 in Mississippi. They had four children—William K. Flowers, Jr.; Perry J. Flowers; Madelyn M. Flowers; and Edwina L. Flowers. In 1924 Flowers moved his family to Dallas where he hoped to establish a private practice. Prior to opening his own practice he worked with Dr. Walter McMillan.
In 1925 he constructed a two-story office building called the Flowers Building on 2317 Hall Street. He also leased office space to other businesses such as the Atlanta Life Insurance Company, Universal Life Insurance Company, Dr. A. E. Hughes, and attorneys Dwayne and Roger Mason.
Flowers was a charter member of the Dallas Negro Chamber of Commerce (now Dallas Black Chamber of Commerce) and in 1926 he chaired its executive committee. He was also active in the Moorland branch of the Dallas YMCA. During World War II he provided volunteer medical services to the draft board.
Toward the end of his career Flowers shared his offices with his two sons, W. K. Flowers, Jr., a medical doctor, and P. J. Flowers, a dentist. In 1956 his son, William Jr., was one of the first black physicians admitted to the staff of St. Paul’s Hospital. Flowers Sr. practiced medicine at his office building until his death. He died on August 30, 1957, while on the way to St. Paul’s Hospital after having a heart attack. He was buried at Carver Memorial Park in Dallas.