High Quality Content by WIKIPEDIA articles! 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, and 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.