




how long it took America to build things: transcontinental railroad: 6 years (1869) Empire State Building: 410 days (1931) golden gate bridge: 4 years (1937) hoover dam: 5 years, finished 2 years early (1936) the pentagon, largest office building on earth: 16 months (1943) alaska highway, 1,700 miles through wilderness: 8 months (1942) a liberty ship: 42 days average, one built in 4 days as a stunt (1943)





















