Abstract: For a stretch of over 400 miles and spanning the state of Indiana, water in the Wabash River supposedly flows freely. In fact, the U.S. Army Corps of Engineers describes the Wabash River as containing the longest free-flowing stretch of water east of the Mississippi. However, the Wabash hasn’t always been free-flowing. For more than a hundred years the Wabash was the site of extensive engineering efforts aimed at making the river navigable for large ships, as local, state and federal actors sought to transform this sandy serpentine river into a water highway that would connect the waters of the Ohio River with those in the Great Lakes. Among the agencies involved in attempting to engineer the Wabash into a navigable stream, the U.S. Army Corps of Engineers was most active. From 1872 to 1902, Congress allocated the Corps more than $24-million to ‘improve’ the Wabash. On the Wabash, these improvements included the construction of dam and lock systems to provide increased draught, bank cribwork to deter erosion, levees to prevent flooding, as well as modifications to the river channel itself, such as dredging of rock bars to deepen the channel. However, with each of these interventions the Wabash pushed back. By the early 1900s, little evidence of past improvements to the Wabash were visible, as the river had redeposited snags and consumed prior interventions aimed at increasing the river’s depth.
While scant evidence of these historical improvements remain visible today, archival records from the Corps, including historical reports and survey maps, provide a fine-scale representation of how the Wabash River appeared in the past. Using methods developed in environmental history and Historical GIS, this paper analyzes the lower Wabash River as an envirotechnical system, examining the feedbacks that occurred between technology and hydrology over a 110-year period between 1820-1930, and demonstrates the utility of digitizing historical maps to understand the evolution of surface water across a landscape. By comparing these results with contemporary environmental datasets and authoritative narratives, we see a floodplain that has been significantly altered by human activity, and a river whose waters flow freely over the failed technologies of the past.