Keystone Bridge Company
| Company type | Bridge Company |
|---|---|
| Industry | Civil Engineering |
| Founded | 1865 |
| Headquarters | Pittsburgh, Pennsylvania |
Key people | Andrew Carnegie |
| Products | bridge construction construction |
Established in 1865 by Andrew Carnegie, the Keystone Bridge Company became a leading American firm specializing in bridge construction. In 1900, it was among the 28 companies merged to form the American Bridge Company. Keystone's expertise encompassed building steel, wrought iron, and wooden bridges for both railroads and roadways.
The firm held patents related to wrought iron bridge designs and also produced wrought iron columns used in architectural projects. Thomas Carnegie acted as the company's treasurer for nearly two decades, from its inception until his passing in 1886.
History and architectural features
Keystone Bridge Company is renowned for constructing the Eads Bridge in St. Louis, completed in 1874 and still operational today. Numerous bridges built by Keystone are recognized on the U.S. National Register of Historic Places.
In 1901, Carnegie divested his steel enterprise to J.P. Morgan.
Selected significant projects include:
- Fairground Street Bridge (1895), crossing ICG RR yard, Vicksburg, MS (Keystone Bridge Co.), listed on NRHP
- Hannibal Bridge (1867–69), spanning the Missouri River at Kansas City, MO, constructed for Hannibal & St. Joseph Railroad (Keystone Bridge Co.)
- Nokesville Truss Bridge, located northeast of Nokesville on VA 646 (Keystone Bridge Co.), NRHP-listed
- Oak Ridge Railroad Overpass, situated southwest of Shipman on VA 653 (Keystone Bridge Co.), NRHP-listed
- Pine Creek Park Bridge, traversing Pine Creek in Fairfield, CT (Keystone Bridge Co.), NRHP-listed
- Riverside Avenue Bridge, at Riverside Ave. and railroad tracks in Greenwich, CT (Keystone Bridge Co.), NRHP-listed
- Valley Road Bridge, Stewartstown Railroad, crossing Stewartstown RR tracks over Valley Rd., Hopewell Township, Stewartstown, PA (Keystone Bridge Co.), NRHP-listed
- White Water Creek Bridge, Whitewater Rd. over White Water Creek near Bernard, IA (Keystone Bridge Co.), NRHP-listed
- Windsor Harbor Road Bridge, at Windsor Harbor Rd. over Rock Creek in Kimmswick, MO (Keystone Bridge Company), NRHP-listed
- Keystone Bridge, spanning the North Fork of the South Platte River close to Bailey Co., providing access to a mountain hiking trail (Keystone Bridge Company)