The 1920s and 1930s were a relatively busy period for Steinman. His firm was involved in many significant projects including the Hercilio Luz Bridge (or Florianópolis Bridge, 1926), the Carquinez Strait Bridge (1927, at the time the second largest cantilever bridge in the US), the Mount Hope Bridge and Grand Mère Suspension Bridge (both 1929), the St. Johns Bridge and Waldo-Hancock Bridge (both 1931), the Sky Ride (1933 passenger transporter bridge at the Chicago Century of Progress exposition), the Henry Hudson Bridge (1936, particularly gratifying as this bridge realised his PhD thesis proposal), the Wellesley and Hill Islands Bridge, Wellesley Island Suspension Bridge and Georgina Island Bridge (all 1938 and part of the Thousand Islands Bridge System), the Deer Isle Bridge and the Sullivan-Hutsonville Bridge (both 1939).