Affectionately known as the "City of Bridges," Pittsburgh boasts 446 bridges -- more than any other city in the world, including Venice, Italy. Long before the majestic bridges soared above the Three Rivers, Pittsburgh was a rugged terrain of deep valleys, creeks and rivers, isolating many of the city's residents.
When the first European settlers arrived in the 1700s, they had to cross streams and climb steep hillsides just to travel around the region. To overcome these challenges, the settlers built wooden bridges to connect newly constructed roadways and span the rivers and valleys.
The city's first river crossing bridge, the Monongahela Bridge, was built in 1818 on the site of what is today the Smithfield Street Bridge. The wooden structure was destroyed in the Great Fire of 1845, and it was replaced by a wire rope suspension bridge designed by John Roebling, who later designed the Brooklyn Bridge.
Increasing weight from additional traffic resulted in the closure of Roebling's Smithfield Street Bridge in 1881.
Using that bridge's standing stone piers, Gustav Lindenthal designed the modern Smithfield Street Bridge with expansion in mind. Since it opened in March 1883 there have been four major modifications, two of which widened the span. It is oldest steel bridge in the United States.
Throughout the 1900s, as the region's population boomed, Pittsburgh waged a massive road and bridge campaign with the development of the Interstate Highway System. The result was a variety of bridge designs, including suspension, cantilever and arch, mostly produced from local steel.
Most recognizable is the only trio of identical bridges in the world, the Roberto Clemente, Andy Warhol and Rachel Carson suspension bridges, which carry traffic across the Allegheny River to Pittsburgh's North Side. These and the hundreds of other Pittsburgh bridges not only connect our region's neighborhoods and residents, but add to the city's unique and beautiful skyline.
Visitors to the Heinz History Center can learn more about the bridges of Pittsburgh in the long-term exhibit, "Pittsburgh: A Tradition of Innovation." For more information, please visit www.heinzhistorycenter.org.