19th Street Bridge
The 19th Street Bridge is the oldest surviving wrought iron bride, and the oldest extant bridge erected for vehicular use, in the state of Colorado. It spans the South Platte River at Nineteenth Street, connecting Ballpark and Lodo with the residential areas of Old Highlands in northwest Denver.
Backstory and Context
After the discovery of gold in the South Platte River in 1858 droves of prospectors and settlers made their way to the Rocky Mountains of Colorado. At the banks of the South Platte River and Cherry Creek formed a number of settlements, including Denver which over time grew into a bustling city. In the earliest years the South Platte River was spanned by a chain of wooden bridges, most of which were destroyed by a series of floods that occurred between 1864 and 1885.
The earliest people to settle in the area of the 19th Street Bridge were German immigrants, who allegedly chose the location because it was a convenient spot for them to do their laundry (Wiberg, 1976). They first settled in the area known as Highlands, across the river from the railroad yards and warehouse district of Denver. In March 1875 plans started for the construction of a bridge to connect the two sides of the river, and in October the following year construction started on a timber bridge spanning the South Platte. However, the wooden bridge’s condition degraded quickly, and in 1878 a child died after falling from the bridge – an event that was blamed on the City Council for not ensuring its integrity. A succession of floods in 1878 and 1884 caused serious damage to the city’s wooden piers and bridges. In 1888, through a collaborative effort between Arapahoe County and the City of Denver, the wooden structure was replaced with a stronger prefabricated cast iron bridge made by the Missouri Valley Bridge and Iron Works of Kansas.
The two-span bridge was made in a Pratt truss form, which was one of the most commonly used in nineteenth century America after being designed in 1844by the Bostonian engineers Thomas and Caleb Pratt. It was built at a total cost of around twenty four thousand dollars. It is a little over two hundred feet long and twenty two feet wide, with five panels on each side and deep I-beam upper struts. The structure itself is made of wrought iron (metal that has been heated and then worked with tools) upon robust stone ashlar pillars, whilst its ornamentation is made of cast iron (metal that has been melted and poured into a mold before being allowed to cool). It originally had a timber deck, which was replaced in 1965 with the asphalt and corrugated iron seen today. The bridge is beautifully designed, with cast iron newels and latticework on the cantilevered sidewalks, and embellished finials and cresting on either end.
Due to the effects of weathering and chloride contamination, the bridge was closed to automobile traffic in 1986, just short of one hundred years of use. Although there were plans to convert the bridge into a viaduct in the late 1890s, these were abandoned by 1904 and the bridge remains in an excellent state of preservation to this day. It is open to pedestrians and cyclists, but vehicles must use the nearby automotive bridge to cross the South Platte.