Zenas King was the founder of King Iron Bridge & Manufacturing Company, later known as King Bridge Company. Mr. King was born in Vermont in 1818, and became a salesman for a farm implement company. He was also known for being a successful carpenter.
In 1858, King decided to get involved in the bridge company, by becoming a salesman for Thomas Moseley, a Cincinnati bridge fabricator who worked on designing tubular members for arch style truss bridges.
While King would establish a partnership with Peter Frees in 1861, this partnership would quickly dissolve and King would retain the bridge portion of their partnership. King began his own company in 1871, known as the King Iron Bridge and Manufacturing Company. He opened his shops in Cleveland.
King quickly became one of the largest bridge builders in the United States, mainly building wagon bridges, particularly with his patented Bowstring design.
King made the bridge business a family one, with many of the leaders of the company of the King name. Zenas died in 1892, and his eldest son James took over the company, renaming it King Bridge Company.
While a number of sources suggest that King was building railroad bridges as far back as the 1870s, no evidence has been found thus far of widespread railroad bridge building before the 1890s. At least one span was reportedly built in 1880, in Cleveland. It appears that most railroad spans were built after Zenas died, with significant railroad bridge production beginning in 1895. Railroad work mainly consisted of steel girders, but some trusses were also built for various railroads. In addition, a number of movable bridges were built for various railroads as well.
Although King Bridge Company entered the 20th Century a strong company, anti-trust lawsuits would create a financial burden for the company. After James died in 1922, the company closed in 1923. Notably, this is one of the few companies at the time not to be merged into American Bridge Company, despite there being much speculation of such a merger.
Today, many King spans survive. While most spans built were for road use, several railroad spans also survive. King was known to have worked with the Chicago & North Western Railway, the Chicago, Burlington & Quincy Railway, the Cleveland, Cincinnati, Chicago & St. Louis Railway, the Missouri-Kansas-Texas Railroad and the St. Louis-San Francisco Railroad (Frisco), among others.
Further details of the history of this company can be seen at the King Bridge Company Museum website.
A sample of plaques and projects completed by King Bridge Company can be seen below. It seems that King had at least a few different style plaques for railroad bridges, including a long rectangular plaque, a square plaque, a decorative portal plaque and a square plaque with beveled corners. Fortunately, many of the standards are available online, meaning the official names of each plaque have been included below.