Leon Solomon Moisseiff was a prominent suspension bridge engineer in the United States during the 1920s and 1930s. Born in Riga, Latvia, he emigrated to the United States in 1891 and later graduated from Columbia University with a degree in civil engineering. Moisseiff is best known for his contributions to suspension bridge design, including the Manhattan Bridge, George Washington Bridge, and Golden Gate Bridge. He developed the "deflection theory," which proposed that longer suspension bridges could be more flexible and thus better withstand wind forces.However, his reputation suffered a blow due to the collapse of the Tacoma Narrows Bridge in 1940, just four months after its completion. This event is often studied in engineering courses as a cautionary tale about the importance of considering aerodynamic stability in bridge design.
