Pacific Shortline Bridge, U.S. Route 20,spanning Missouri River, Sioux City, Woodbury County, IA

Significance: The Pacific Short Line Combination Bridge was the work of three prominent names in the late 19th century American engineering: J.A.L. Waddell (chief engineer), Charles Sooysmith's Sooysmith & Company (foundations and piers), and the Phoenix Iron and Bridge companies (fabricators and erectors). The dates of the Pacific Short Line Bridge (1890-1896) make it among the early large-scale works of both Waddell and Sooysmith. It is also one of Waddell's and Phoenix's earliest efforts in steel bridge design and construction, at a time when the use of steel was still not universally accepted, particularly for spans of the size of the Pacific Short Line bridge. As constructed, the bridges consisted of two 470' rim-bearing, through Pratt swing spans and two 500' Pennsylvania through trusses. All spans were pin-connected. The bridge was built at least partially as Sioux City's response to changing developments in Upper Missouri transportation systems, as westward running railroads supplanted steamboats, which were instrumental in the city's early growth, as the principal carriers of people, goods and raw materials during the 1880's. The bridge also stands as a rather spectacular relic from the late 19th century speculative scheme to build a transcontinental "short line" from Sioux City to Ogden, Utah. Although the Pacific Short Line failed after two years (a lifespan common to other railroad ventures of its kind), businessmen of Sioux City saw the bridge through to completion. The transcontinental plans were not realized, but the bridge provided needed competition for the 1888 Union Bridge at Sioux City, controlled by the Chicago and North Western Railroad, and gave Sioux City businessmen access to potential markets in northeastern Nebraska. Perhaps the most long-lasting impact of the Pacific Short Line bridge was that its wagon, streetcar and pedestrian paths, eventually expanded to a full four lanes of highway, served to connect Sioux City physically and psychologically to areas to the west and south, resulting in the development of South Sioux City and environs as part of Sioux City's market and metropolitan area.
Unprocessed Field note material exists for this structure: FN-1
Survey number: HAER IA-1
Building/structure dates: 1896 Initial Construction
Building/structure dates: 1919 Subsequent Work
Building/structure dates: 1957 Subsequent Work
Building/structure dates: 1962 Subsequent Work