After high school he went to work at the Henry L. Simons Company, which was known for their exclusive residential building designs. Smith later worked for Edward James Associates before starting his own firm.
This online collection in the University Libraries' Digital Media Repository contains examples of 241 different projects dating from 1932 to 1969. The drawings are mostly designs for private residences in Indianapolis; however there are some examples of commercial additions and remodeling jobs. Other drawing sets are for vacation cottages, a fraternity house, stadium, recreation center, Union Chapel Cemetery, and the Indianapolis Mirror Company. Most of the work is by Smith but a few projects are by architects Rollin Shuttleworth and Charles D. Ward.
The collection was donated to the Drawings + Documents Archive by Smith's son, Greg Smith, in 2012.
Images: Mr. and Mrs. Gordon T. Kelly residence presentation drawing, 1940; M. Carlton Smith photographic portrait, 1930s. M. Carlton Smith Architectural Drawings, Drawings + Documents Archive, Ball State University.