Keystone Bridge Company was created in 1865.
Keystone Motor Company of Philadelphia was created in 1900.
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Keithsburg Bridge Company was created in 1881.
Sibley Bridge Company was created in 1887.
Railroad Bridge Company was created in 1853.
King Bridge Company was created in 1858.
American Bridge Company was created in 1900.
Quincy Bridge Company was created in 1866.
Quincy Memorial Bridge was created in 1928.
Michigan Central Bridge Company was created in 1896.
St. Louis Bridge Company was created in 1878.
Detroit River Bridge Company was created in 1898.