Construction of the Eads Bridge, connecting Illinois and Missouri in East St. Louis, began on this day in 1867.

The Eads Bridge was the first bridge made of cast steel and, at the time, was the longest arch bridge in the world. With the help of underwater work stations, bridge designers were able to sink piers well into the gravel bedrock more than 100 feet underwater – an engineering feet unheard of at the time. After more than seven years of construction, the Eads Bridge opened in June of 1873 at a final cost of $7 million.

Today, the Eads Bridge carries more than 8,000 vehicles everyday on its upper deck. Rail lines on the lower deck carry MetroLink trains connecting the East St. Louis riverfront with downtown St. Louis.

Learn more:
Read more about the Eads Bridge designer James Buchanan Eads