David Bernard Steinman (June 11, 1886 - August 21, 1960) was an American structural engineer. He was the designer of the Mackinac Bridge and many other notable bridges as well as a published author. He grew up in New York City's lower Manhattan, and lived with the ambition of making his mark on the Brooklyn Bridge that he lived under. In 1906 he earned a bachelor's degree from City College and in 1909, a Master of Arts from Columbia University and a Doctorate in 1911. He was awarded the Franklin Institute's Louis E. Levy Medal in 1957.
David Steinman built bridges in the United States, Thailand, England, Italy, Haiti, Puerto Rico, Canada, Korea, and Iraq. He had a literary bent, and was a published author with several books, articles in advancement of his craft, and even had children's books and poetry to his credit.
Steinman grew up the son of immigrant workers in New York City, and was raised in the shadows of the Brooklyn Bridge. He worked to put himself through both the City College of New York, graduating Summa Cum Laude in 1906 and then Columbia University, where he completed three additional degrees culminating in a PhD in Civil Engineering. His PhD thesis was on a steel truss arch design for the Henry Hudson Bridge.
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 Deer Isle Bridge and the Sullivan-Hutsonville Bridge (both 1939) (many of these are part of the Thousand Islands Bridge System).
Steinman became president of the American Association of Engineers and campaigned for more stringent educational and ethical standards within the profession. He also founded the National Society of Professional Engineers in 1934 serving as its first president. By the mid 1930s Steinman had a professional reputation as one of the pre-eminent bridge engineers of the United States
At the age of 63, Steinman took interest in poetry. Many people wrote to him saying his bridges represented poems. This inspired him to start writing. His love for bridge building was reflected in his writing, which can be seen in the titles of two of his poems, “The Bridge” and “I Built a Bridge”. He received much recognition for his poetry; many poems were published in various newspapers and magazines.