Bridge No. L-2162 is historically significant as an excellent, unaltered, example of a regional, vernacular variation on the small, rural, reinforced concrete bridge, particularly the variety of reinforced concrete arch bridge built by, or attributed to, Perley N. Gillham of Luverne, Minnesota. There is a very large collection of similarly designed, aesthetically outstanding, early reinforced concrete bridges in southwestern Minnesota. This bridge has additional engineering significance as being one of the largest reinforced concrete arch bridges built in Minnesota during the state's first decade of concrete-bridge construction (1900-1910).
This bridge is one of at least twelve strikingly similar bridges in Rock County and one in neighboring Nobles County that have the identification "P.N. Gillham" scribed in the concrete. There are at least sixteen additional bridges in the county that do not bear Gillham's name and have design elements so similar to the confirmed Gillham bridges as to allow attribution to him. Confirmed dates of Gillham bridges, as indicated on the bridge, range from 1908 to 1913. Attributed bridges have unconfirmed dates ranging from 1901 to 1920. Although the exact date of the bridge is unknown, the county highway engineer attributes the bridge to 1907. This may be the "Split Rock" bridge noted in the county commissioners' minutes of December 1, 1908, and mistakenly located on a nonexistent section 25/35 line. The correct location for L-2162 is 25/26. If so, the bridge cost an estimated $1800 to $2000.
This bridge is the largest, in both overall structure length and span length, of all the known or attributed Gillham bridges in the county. It also is the largest known reinforced concrete arch bridge in Minnesota built before 1910. Bridge No. 2165 in McLeod County, built ca. 1910, has an overall structure length of 66 feet. Although it should be noted that the construction dates of both bridges are not confirmed, it is clear that the Bridge No. L-2162 ranks among the largest of Minnesota's early reinforced concrete arch bridges.
The Gillham reinforced-concrete arch bridges share the following characteristics. Gillham's bridges are low-rise, single-span, elliptical arch, usually 20-foot to 30-foot span, with a scribed line in the arch-ring edge. They are filled-spandrel, barrel-arch in construction, with wing-wall abutments, almost U-type and feature continuous coping. They have a distinctive slab railing, over arch only, with cylindrical end posts and continuous coping. They have distinctive, decorative, concrete molding found along the lower edge of all coping. The names and dates related to construction are scribed or pressed into the top surface of the railing coping. Bridge floors may be arched over the span arch or may be straight. Railings and copings may also be arched or straight. End posts are centered on the railing slab or flush with the inside of the slab. End posts may terminate at the floor coping or may continue below, marking the abutment line. Most of these characteristics, particularly the railing, coping and molding details have not been observed in other Minnesota bridges. Bridge L-2162 possesses all the Gillham features, but in slightly larger scale, matching its larger dimensions.
Despite a considerable amount of research in state and county sources, very little has been discovered about Gillham and his bridges. Perley N. Gillham arrived in Luverne, the county seat, in 1875, following his brother Edwin, who had come to the community in 1868 as a stage driver. Edwin was born in Illinois in 1845. The birth date and location for Perley is not known. He first appears in the county commissioners' records for plastering work in 1875, and periodically is mentioned in connection with various contracting work. His name is first associated with a bridge in 1883, but only for repairs. In 1887, he was appointed superintendent of construction for the new county courthouse and in 1900 was awarded the contract for construction of a new county jail. From the 1890s onward, his name appears regularly for miscellaneous county work, including building, bridge and road contracts. Unfortunately, the county commissioners' minutes rarely discuss bridge work in any detail and usually do not mention the bridge type or the contractor's name. The March 23, 1934, Rock County Herald referred to Gillham as "our first contractor and builder," noting that "many of the prominent buildings of the city at the present time were built by him." Even his date of death is a mystery. Newspaper records suggest that he was alive in Luverne at least as late as 1933 or 1934, but state records have located no death certificate for Gillham between 1930 and 1950.
Where did such an obscure plasterer and general builder and contractor, living and working in what is among the state's most remote counties, learn to design and build reinforced concrete arch bridges during the earliest years of reinforced concrete bridge construction? Other early Minnesota reinforced concrete arch bridges, such as those built around 1900-1905 for the Twin Cities Rapid Transit Company are clearly different from Gillham's designs. The only hint of an outside influence on Gillham is found in the Fritz von Emperger designed small, Melan-arch concrete bridge, which was built near Rock Rapids, Iowa, in 1894. Rock Rapids is only a mile south of the Minnesota state line and less than three miles due south from Luverne. The only published photograph shows a bridge whose proportions are almost identical to Gillham's designs, and even the reported dimensions (either 30-foot or 36-foot span, depending on the source; it may be a 36-foot structure with a 30-foot clear span and a low rise of 6.5 feet) are similar to Gillham's. Adding to the possible connection is the reported name of the contractor, Minneapolis bridge builder William S. Hewett, who would become significant for his pioneering work in reinforced concrete. One source states that Hewett "had a blanket contract for building all county bridges in two or three counties in Iowa for the year 1894." It is known that, at the time, William was the agent and a joint proprietor with his uncle Seth in S.M. Hewett & Company, bridge builders. Seth M. Hewett had started out as lumberman and wooden-bridge builder in Hamburg, Iowa, and in the 1880s appears in the Rock County commissioners' minutes for bridge work. In fact, Hewett received the 1884 contract to replace the same Ash Creek bridge that Gillham had repaired a year earlier, suggesting that there were opportunities for Gillham to meet the Hewetts and, perhaps, establish a relationship that later led to an exchange of information about reinforced concrete and the Iowa bridges.
While very intriguing and suggestive, the evidence that P.N. Gillham's bridges are vernacular descendants of America's first Melan-type bridge remains circumstantial and awaits further research. Nevertheless, it is clear that P.N. Gillham's reinforced concrete arch bridges constitute a substantial and significant body of vernacular work. Bridge L-2162 is a excellent, unaltered, documented example of Gillham's bridges.