The growth of Will County can be directly traced to the building of the Illinois and Michigan Canal. Completed in 1848, and about one hundred miles long, the I&M Canal was the final link in a national plan to connect different regions of North American via waterways.

With the help of many foreign-born immigrants, the 6-foot deep canal was dug through the northern part of Will County and connected the cities of Channahon and Joliet to the east and west sections of the canal.

The Will County towns of Joliet, Lockport and Channahon were three towns, that prospered in the 19th century because of the transportation network which tied the county with Chicago and the East Coast markets.

The construction of the I&M Canal forever changed the nature of trade in the Illinois River valley. When the canal opened in 1848, trade that once was channeled through St. Louis now was directed to Chicago.

Over time, the canal stimulated agricultural development in the region and prompted the growth of businesses in Chicago that were directly dependent on agriculture. In the first decade after the canal opened, the variety of products transported along the canal included wheat, corn, oats, flour, sugar, salt, pork, coal, stone and lumber.

The I&M Canal crosses the DuPage River on the upstream side of the Channahon Dam. The canal is separated from either side of the river by a set of locks.

Lock No. 6 on the north side of the river maintains the canal's water surface that
is about 7 feet above the DuPage River.
Lock No. 7 is located south side of the river, and is the last lock before the canal flows west towards Aux Sable Aqueduct.

The dam that was constructed between Lock No. 6 and No. 7 was to impound the DuPage River and cause the water to be diverted into the canal as a natural feeder. Connecting the canal directly to the river proved to be more economical than constructing an aqueduct over the river, and it provided a perfect, natural solution to bring needed water into the canal.

Most of the locks and wooden gates constructed along the I&M Canal followed a common set of specifications and were based on a 10-foot lift. Variations in the designs did exist along the route, such as in Lock No. 1 and Lock No. 2 in Lockport.

To assure a 10-foot lift lock, the I&M Canal locks required an 18-foot-wall height and a foundation that was more than 11 feet thick. The typical lock chamber measured 110 feet long by 18 feet wide and would accommodate canal boats that were constructed to meet these dimensions.

The Then photograph shows a view of the northern portion of Lock No. 7. Notice the six young children sitting on the large wooden beam. These large tapered beams, called balance beams, are long arms projecting from the landward side of the lock gate over the towpath. These heavy wooden timbers were attached to the top of the lock gate and chamber lock wall.

As well as providing leverage to open and close the heavy gate, the beam also balances the (nonfloating) weight of the gate in its socket, and so allows the gate to swing more freely.

The Now image shows a similar view of Lock No. 7 today. The wooden balance beams no longer exist at the Channahon locks, so the students are sitting on the protective wooden fences that have since been erected around the locks.