A bit of ingenious engineering is required to construct aqueducts to cross streams, creeks and rivers along the Illinois and Michigan Canal route.
Along the 96-mile trek through the wilderness, the I&M Canal needed a series of 15 locks to navigate the 141-foot elevation change from Chicago to the Illinois River. The canal route also needed four aqueducts to carry the canal across other bodies of water.
Canal engineers had to design and construct four aqueducts to carry the canal over rivers and creeks. The four principal aqueducts built were over Aux Sable and Nettle Creeks and the Fox and Little Vermilion Rivers.
The largest of the aqueducts constructed was built over the Fox River in Ottawa by the local construction firm of David Sanger & Sons. The original Fox River aqueduct in Ottawa was constructed in a similar fashion to other aqueducts along the canal.
The 1848 version was built of six, timber Howe truss spans resting on seven limestone piers and two abutments. When completed, the aqueduct measured 464 feet in length.
The wooden towpath bridge, which ran along the south side of the structure, fell into disrepair after 1870 when mule teams were no longer necessary. The Illinois Traction System extended the piers from the old timber towpath and created a railroad crossing over the river in 1903.
In 1918, the federal government provided funds to improve western sections of the canal, and the four aqueducts were replaced with steel.