Before the establishment of the North Carolina State Highway Commission (the predecessor to the N.C. Department of Transportation) in 1915, North Carolina's counties were primarily responsible for the construction and maintenance of highway bridges.
Most counties continued the tradition of simple, craftsmen-built, timber bridges, or they bought from companies that sold prefabricated, metal-truss bridges.
The trusses and a few other bridge types, such as the steel stringer and reinforced concrete arch, are among the last remnants of the county bridge-building era in North Carolina, which came to an end in 1931 when the State Highway Commission took over all former county roads and bridges.
Bridge companies varied in size from larger firms that operated nationally and were backed by major steel makers to smaller independent contractors operating within a limited geographic area.
The big companies, particularly U.S. Steel's American Bridge Company, which was established in 1901 and gained control of about 60 percent of the nation's fabricating capacity, had advantages of scale and vertical integration and dominated the prefabricated bridge market. Dozens of smaller companies filled market niches, especially selling trusses to local governments in rural areas. Many smaller companies built their own patented truss designs or had proprietary details or ways of forming and connecting the truss members.
Among the most active companies in North Carolina were the Roanoke Iron & Bridge Works and the Virginia Bridge & Iron Company, both of Roanoke, Virginia. These and other companies established business offices in North Carolina, but the only known fabricator with shops actually located in the state was Carolina Steel & Iron Company of Burlington and later Greensboro. The company operated from about 1905 through the 1910s when it was bought out by Virginia Bridge & Iron. Like many smaller fabricators of this period, Carolina Steel & Iron built lightweight truss designs for county roads.