Bridges

Cabin John Aqueduct, designed by Montgomery C. Meigs, conveys drinking water from Great Falls, Maryland to Washington, D.C. It was the longest stone masonry arch in the world for nearly 40 years. The segmental arch of the bridge has a span of 220 feet and a rise of only 57 feet. The main arch ring is built of cut and dressed granite. The secondary arch ring is radially-laid sandstone, of which the rest of the bridge is also constructed. 

On May 24, 1883, with schools and businesses closed for the occasion, New York celebrated the opening of the Brooklyn Bridge. Also known as the Great East River Bridge, it was built over 14 years in the face of enormous difficulties. Deaths, fire in the Brooklyn caisson, and a scandal over inferior materials all added to the turmoil. The bridge is one of the most well-recognized symbols of American engineering, and remains the unofficial Eighth Wonder of the World.

A product of the Northern California Gold Rush, the Bridgeport Covered Bridge is believed to be the longest, single-span, wooden covered bridge in the United States. Crossing the south fork of the Yuba River at a span of 233 feet, the bridge was built by the Virginia City Turnpike Company as part of a 14-mile toll road authorized by the California state legislature. The toll road was an essential link connecting Virginia City, Nevada, and the silver-producing Comstock Lode with the centers of California commerce.

Nicholas Montgomery Powers built the bridge. It was first constructed behind the village, then taken apart and reassembled over the stream. Some residents questioned the idea of re-constructing it, but Powers was so confident of the bridge's durability that he sat on the roof when the final trestles supporting it were removed. From his perch he reportedly said: "If the bridge goes down, I never want to see the sun rise again!"

Soon after gold was discovered at Sutter's Mill near Sacramento in 1848, General John Bidwell found gold near the Middle Fork of the Feather River. His discovery brought hordes of miners to the scene and Bidwell Bar was born. The Bidwell Bar Suspension Bridge over the Feather River was one of several suspension bridges built in the region in the 1850s, and is the only one that remains.

The longest steel-arch bridge in the world for 46 years, the Bayonne Bridge continues to be celebrated today as a major aesthetic and technical achievement. The 1,675-foot bridge replaced a ferry service which until then was the only means of crossing from  the Bayonne peninsula to Staten Island. While providing this essential link in the transportation network of greater New York City, the bridge's mid-span clearance of 150 feet also allows for unobstructed navigation on Newark Bay, the main shipping channel to the inland ports of Newark and Elizabeth, New Jersey.

Hardy fishermen and their families have long inhabited Bailey Island, which was settled in the 1720s. Ordinarily, they did not mind crossing to the mainland in their fishing boats. But before the Bailey Island Bridge was built, during certain seasons of the year when violent storms battered the coast, it was impossible to leave the island.

Work began in 1887 on the high-level truss "Winner Bridge" crossing the Missouri River at Kansas City. The piers were completed in 1890, but for financial reasons the project was suspended. John Alexander Low Waddell, renowned civil engineer, prepared an alternate design for a lift bridge in 1895, which would ultimately be built as the Armour-Swift-Burlington Bridge.

"An essential part of the human experience is to create an aesthetic atmosphere."

The George Washington Bridge represented a departure in suspension bridge design. Chief Engineer O.H. Ammann developed a system of stiffening trusses that offered greater flexibility and saved the project nearly $10 million. Initially, just six of the upper eight lanes were paved, but Ammann designed the bridge to easily accommodate a future lower level.

Swiss-born O.H. Ammann (1879-1965) was Chief Engineer for the Port Authority of New York and New Jersey during the bridge's construction.