He had an early medical practice in Jellico, Tennessee.[8] For 17 years he served as the city physician in Knoxville, Tennessee; and worked as a doctor in Knoxville from 1900 to 1939.[3][4] Green was one of the founders of Knoxville Medical College (1900–1910).[4][9]
In 1900, Green became an alderman (or council member) in order to represent his neighborhood in the fifth ward, he was the first Black alderman in the city.[2] He remained an alderman until 1912, and it took another 62 years before the Knoxville city council had another Black alderman.[10][11][12] In 1910 and 1911, Green served as the chairman of the "Colored Department" at the Appalachian Exposition, held in Knoxville.[13]
He served as president of the National Medical Association, elected in 1922;[7][14] and was the founding president of the National Hospital Association in 1923.[3][4]
In 1922, Green married school teacher Henri Henderson; and together they had two children.[3][8]
The Green School (sometimes refer to as the "Colored High School" in the early years) in Knoxville was named for him, and opened in 1909.[5][16] Green was profiled in the book, The Knoxville Negro: Emphasizing the Great Era of Progress Prevalent in Negro Knoxville Today (1929) by Bartow G. Wilson.[17]