Dr. Clarence F. Holmes, practiced dentistry for 56 years from an office in Denver’s Five Points neighborhood. He was the Denver Dental Society’s first African-American member and was the founder and 20-year president of the Cosmopolitan Club, an organization that promoted interracial and interfaith understanding.

Clarence Fitzhugh Holmes was born May 21, 1892 in Denver, Colorado, after his parents moved from Washington D.C. He attended Ebert School and graduated from Manual High School in Denver in 1913, and Howard University and Howard University College of Dentistry in Washington D.C. (B.S. 1917, D.D.S. 1920).

After college, Homes married Fairfax Butler Richey. The couple moved briefly to Pueblo, Colorado before making Denver their home in 1931.
Holmes opened a dental practice in Denver’s Five Points neighborhood. Although he was not the first licensed black dentist in Colorado, a distinction that belongs to Dr. Ernest McClain (licensed in 1907; practiced until 1948), Holmes was the first African American dentist to join the Denver Dental Society. Knowing that people had very little to no money during the Great Depression, Holmes offered free extractions to his patients.
Holmes retired from his dental practice in 1975.

Holmes helped to found the Colorado-Wyoming branch of the National Association for the Advancement of Colored People (NAACP, pictured right), a group he joined while at Howard University. He also helped to found the Glenarm YMCA, which unlike other Denver YMCA branches was open to African Americans.

sources:

https://www.findagrave.com/memorial/31410450/clarence-fitzhugh-holmes