By the turn of the 20th Century, most of Kendall County’s old water-powered grist and sawmills had either completely disappeared or had switched to steam power.
That might seem puzzling given that the water powering all those mills was free, while steam engines require fuel of one kind or another that has to be purchased. As it turns out, though, while the water that powered mills might have been free, actually turning water into hydraulic power was pretty costly. Couple that with the economics of improved transportation and the economies of scale industrialization created, and it gets a lot easier to see why water-powered mills disappeared from the landscape.
Starting with the era of settlement in the 1830s, enterprising millwrights built sawmills and gristmills on almost every sizable stream in Kendall County. The Fox River had its share of mills of various kinds, of course, but so did local creeks including Blackberry, Morgan, Big Rock, and Waubonsie.

According to the county’s first historian, the Rev. E.W. Hicks, by 1846, Kendall County’s population totaled 5,600 people and “Their sawing and grinding was done by fourteen saw and grist mills.”
To create the waterpower to run their mills, millwrights first had to build dams. During that era, they were simple walls built across streams with no floodgates. The technology of the day called for putting together triangular timber frames that were than hauled into the stream and secured to the bottom with forged iron stakes. The open frames were then filled with rocks and rubble. The vertical upstream side of the dam was faced with planks to hold the rubble in place, while the slanted downstream side was also covered with planks to make a smooth surface for the water running over the dam.

Millraces were dug around one or sometimes both ends of the dam and were generally faced with flagstone easily mined along the banks of the county’s streams. These millraces could be either simple, powering one mill or longer and more elaborate powering multiple mills. The long Montgomery millrace powered two mills, while the millrace at Yorkville powered Black’s paper mill as well as Yorkville’s first grain elevator via an overhead wire cable and pulley system.

Here in Oswego, the dam was sort of anchored into the bedrock exposed on the two riverbanks. The mills were then built in such a way that their millraces ran through their basements, where the waterwheels, and later the turbines, were located. That had the advantage of eliminating the need for longer races that could be maintenance headaches. The gristmill on the west bank was built first, followed by the sawmill on the east bank. A furniture factory was eventually added to the sawmill. A small chest of drawers manufactured there is on exhibit at Oswego’s Little White School Museum.

The fast millrace water powered the millwheels. Because of our generally flat topography, many of our early mills used horizontal tub wheels although vertical undershot wheels that we generally think millwheels ought to look like were not uncommon, either. One county mill used an undershot wheel, powering equipment using water flowing under and not over it. Huge at 24-feet in diameter, the sawmill it powered was located on the Fox River at Millbrook.

As soon as possible, those early tub and undershot wheels were replaced by turbines imported from back East. A later turbine wheel from Gray’s Mill is on exhibit near the riverbank in the park just upstream from the Mill Street Bridge in Montgomery.
Early on, sawmills were as, if not more important, than gristmills. They used vertical steel sawblades to cut local timber into lumber for buildings and fences. In the county’s oldest buildings the evidence of their vertical saw cuts are still clearly visible, looking much different than the spiral saw marks made by later circular sawblades.
The era of local sawmilling ended surprisingly soon as cheaper lumber began to flow into Chicago aboard sailing ships from Michigan and Wisconsin. The fate of Jackson’s Millbrook sawmill mentioned above was typical, as Hicks reported in 1877: “But the gang saws of Michigan and Wisconsin at last outstripped it, and left the aged frame to bleach in the sun until a year ago, when the spring freshet bore it away on its bosom to rest in a watery grave.”

Hicks’ comment above also points out one of the other downsides of the county’s water-powered mills—the cost of maintaining them in the face of annual floods, called freshets back in those days. Dams were damaged every year by the annual spring floods, and were sometimes–along with their adjacent mills–entirely destroyed by rampaging ice floes and high water during breakup.
As a result the dams also required constant maintenance. Those timber frames submerged in water tended to rot away and the upstream and downstream plank coverings had to be monitored continually, making for a lot of labor needed to make use of that “free” water. Couple that with the vagaries of water flow at various times of the year, and it becomes clear water power may not be such a hot power source after all. As the Kendall County Record reported from Yorkville on Aug. 21, 1879: “The water in the river is so low that the paper mill had to shut down Tuesday.”
The viability of local mills remained certain through the 1870s. After that two things tended to lead to their disappearance. First was the advent of affordable steam engines. When a steam engine could be installed and run the establishment with no need to maintain a dam, complicated turbines, or worry about low water levels, it made economic sense to switch power sources.

Gradually, the old mills closed down to be replaced by steam-powered mills in more convenient locations, which, in turn, were then made obsolete by the extension of rail lines through the county that carried farmers’ crops and livestock away and brought back manufactured materials, from wheat flour to sawn lumber, at prices no small local sawmill or gristmill could beat or even meet.

While some of the old mill buildings remained—especially ones like Gray’s Mill just north of the Kendall County line in Montgomery or Wing’s Mill In Kendall County’s Fox Township at Millhurst built of native limestone—others were washed away by floods, burned down, or were dismantled and their timbers reused for other purposes. The dams that provided their waterpower were gradually erased by annual spring floods and the breakup of ice in the spring. A few of the dams were maintained by companies that harvested ice from their millponds but the increasing pollution of the Fox River and the development of ice manufacturing equipment eliminated that use as well by the first decade of the 20th Century.

Today, while some of those old dam and mill sites have been totally erased from the landscape, here and there their remains can still be seen if a person knows what they’re looking at—I can see the remains of a dam and the mills that stood at either end from my office window here in Oswego, for instance. And the remains of Montgomery’s long millrace are still visible as a swale extending along the riverbank above the Montgomery Bridge.
But for the most part it’s one more once-important Fox Valley business era that’s almost totally disappeared from our collective memory.