Sanguinet was one of the most important early architects in Texas. His partnership with Arthur and Howard Messer was responsible for the development of Arlington Heights, a prominent resort community. With partner Carl Staats and later partner Wyatt Hedrick, Marshall Robert Sanguinet designed most of the early towers of the Fort Worth central business district. In addition, the firm also designed residences, churches, educational facilities, courthouses, and club buildings in Fort Worth as well as in Dallas, Houston, San Antonio, and Wichita Falls, where branch offices are located.