The Sixth Street Bridge is a self-anchored suspension bridge spanning the Allegheny River between Federal Street on the North Side and Sixth Street in downtown. Opened in 1928, it is one of the three "Sister Bridges," which include the Seventh and Ninth Street Bridges. The Sister Bridges are the only trio of nearly identical bridges built in the United States. The Sixth Street Bridge stands next to the Pittsburgh Pirates PNC Park. In 1998, it was redesignated "The Roberto Clemente Bridge" in honor of the Pirates Hall of Fame player.

Pittsburgh's three "Sister Bridges" include the Sixth, Seventh and Ninth Street Bridges.

The current Sixth Street Bridge is the fourth in a series of bridges that spanned the Allegheny River at this spot. The first was built in 1819. It was a covered wooden toll bridge known as the Allegheny River Bridge, or the St. Clair Street Bridge.

The bridge was so named because Sixth Street in Pittsburgh was then known as St. Clair Street. It was built as a companion to the Monongahela Bridge, which spanned the Monongahela River at Smithfield Street, and was the first bridge to link the cities of Allegheny and Pittsburgh. The Allegheny River Bridge replaced a ferry service that had been in operation at this location.

The Allegheny Bridge Company charged a two cent per person toll to cross. The bridge became a very lucrative venture for investors. By the mid-1850s, the company decided to replace the aging wooden span with a modern suspension design that could carry the increasing traffic flow and allow for trolley service. The toll business had proven so profitable that fares were reduced to one cent per person and there was no charge for women and children.

The St. Clair Street Bridge, shown here in 1890, spanned the Allegheny River between
Allegheny City and Pittsburgh from 1857 to 1892.

In 1857, the wooden Allegheny River Bridge was razed. Renowned architect John Roebling designed the new iron suspension bridge, officially called the St. Clair Street Bridge. The elegant design was the third and final Roebling bridge to be built in Pittsburgh, and was described by one historian as "the first great bridge to span a navigable stream in the United States."

Roebling's reputation for excellence began with the Allegheny Aqueduct Bridge in 1845, followed by the Smithfield Street Bridge in 1846. This second Roebling design replaced the Monongahela Bridge, which burned in the Great Fire of 1845.

By the turn of the century, the suspension bridge, despite it's popularity, was unable to support the ever-increasing vehicular traffic and heavier loads. It was not suitable for the new electric trolley cars and restrictions were posted limiting speed and light vehicle load weight. A new bridge was necessary.

The Roebling suspension bridge was replaced in 1892 with a third structure, a Pratt truss bridge, that was in place until 1926. In 1908, when the City of Allegheny was annexed into the City of Pittsburgh, the bridge was renamed the Sixth Street Bridge.

The Sixth Street Bridge connects Federal Street on the North Shore and Sixth Avenue in 1910.

The Sixth Street Bridge became a free crossing for both vehicles and pedestrians in 1911 when it was purchased by Allegheny County. Due to new regulations issued by the War Department regarding bridge clearances over water levels on navigable rivers, it became necessary to either raise or replace many of the Pittsburgh bridges across the Allegheny River, including the Sixth Street Bridge.

Funded by a 1924 bond issue, the Sixth Street Bridge, along with it's companions at Seventh and Ninth Street, was replaced in 1928, this time with the present-day structure. The new span was the last of the three "Sister Bridges" to be completed between 1924 and 1928. In an unusual move, the Pratt trusses being replaced were lowered onto barges and floated to a new location along the Ohio River between Coraopolis and Neville Island in 1927. The old Pratt trusses continued to serve in their new setting until 1995.

Pittsburgh's new Sister Bridges were built with an unusual, self-anchored suspension design, modeled after a bridge over the Rhine River in Germany. Instead of heavy anchorages to hold the cable ends, rigid towers hold the ends apart. The new bridges were the first of this type constructed in United States, and won an award for beauty from American Institute of Steel Construction in 1929.

The award-winning Sixth Street Bridge in 1940 with it's original paint scheme of green and aluminum grey.

When first opened in 1928, the deck girders of the Sixth, Seventh and Ninth Street Bridges were painted green, and remaining superstructure painted aluminum grey. Years later, in consideration of the City of Pittsburgh's adoption of the official colors of black and gold, the three Sister Bridges were all painted gold yellow, matching the color of several other Golden Triangle spans.

During the construction of PNC Park on the North Shore, there was a popular sentiment in the city that the new ballpark be named after Roberto Clemente, a legendary former Pittsburgh Pirate player. When the naming rights to the stadium were sold to PNC Bank, the city compromised. On August 6, 1998, the Sixth Street Bridge was renamed the Roberto Clemente Bridge. A statue of Clemente, which once stood at Three Rivers Stadium, was relocated to PNC Park and placed near the north shore bridge anchorage.

The Roberto Clemente monument stands next to the bridge that bears his name.

Although open to vehicular traffic on most days, the bridge is closed on Pittsburgh Pirates and Pittsburgh Steelers game days, providing a pedestrian route to PNC Park and Heinz Field. In 2002, architectural lighting was added to the Roberto Clemente Bridge by the Pittsburgh Historical Landmark Foundation. The bridge was lit for the first time on November 20, 2002.

The Roberto Clemente Bridge, with the architectural lighting turned on, in 2012.

The Four Versions of the Sixth Street Bridge (1819-present)