refinished early 20th century single-sided cast iron bridge plaque removed from an old extant chicago & northwestern railroad bridge located just west of downtown chicago. the plaque features embossed lettering with a border consisting of intersecting lines. the bridge manufacturer and date the bridge was constructed are prominently displayed within the raised lines between the mounting holes. the photographs shown above show the plaque in its original setting or location (i.e., bolted firmly against a riveted truss with weathered surface paint). the american bridge company was founded in april 1900, through the jp morgan-led consolidation of 28 of the largest united states based steel fabricators and constructors. the company's roots extend to the late 1860's, when one of the consolidated firms, keystone bridge works, constructed the eads bridge, the first steel bridge over the mississippi river, at st. louis which is still in use today. shortly thereafter, in 1902, the company became a subsidiary of united states steel as part of the steel trust consolidation. it went private in 1987. the company has a long and storied history. while american bridges roots in steel fabrication and construction remain a strength today, the company developed broad based contracting and management resources to service complex project needs. some of american bridges most notable projects are more a testament to construction engineering know how and management abilities than to its historical strength in steel construction. the company pioneered the use of steel as a construction material; developing the means & methods for fabrication and construction that allowed it to be widely used in buildings, bridges, vessels, and other plate applications. as a result, and due to its deep financial resources, american bridge has operated on a national and international scale from the moment of its inception. american bridge produced a number of ships for the united states navy as part of the war effort during world war ii. the town of ambridge, pennsylvania was an american bridge company town (thus the name "ambridge"), and is near their current headquarters of coraopolis, pennsylvania. both municipalities are located on the ohio river near pittsburgh, pennsylvania, with access to many steel suppliers, as well as to waterborne and rail transport, to allow shipment of components and subassemblies. measures 16 x 10 inches.