Sag Bridge is now part of the Village of Lemont, but at one time it was a village in its own right. It boasted a hotel and it had its own post office, a number of businesses, a railroad station, a stop on the electric line between Chicago and Joliet, and a port on the I&M canal. Joshua Bell, who came to Sag Bridge in the 1830s, was the postmaster and owner of the hotel. Although the town soon found it too expensive to continue as a village, it had a school district composed of one of the last one-room schoolhouses in the state, which did not close until 1961. The center of the “town” was roughly where Archer Avenue (Route 171) and Bell Road intersect today.
When the glaciers retreated from Northern Illinois, prehistoric Lake Chicago remained, which eventually receded leaving Lake Michigan. As it receded, it left two valleys, the Des Plaines River Valley and the Sag Valley, on either side of an elevated triangle of land called Mount Forest Island. Sag Bridge was located on the south side of the Sag Valley, and the historic Saint James at Sag Bridge, the oldest continuously-operating Catholic Church in Cook County, was built on the north bluff, in the forests at the western edge of Mount Forest Island. The cornerstone of the church was laid in 1853, but it took six years for the men of the parish to dig stone from a nearby quarry and haul it up the bluff to complete the building.
Before permanent settlement, Mount Forest Island had been inhabited by Native Americans, who valued the land for its vantage point and strategic location. Saint James is said to have been built on the site of an Indian village, possibly an Indian graveyard, and later a French fort. Father Marquette and Louis Joliet stopped there during their exploration.
Many immigrants to Sag Bridge came from Ireland to find jobs digging the I&M canal in the 1840s, and when the canal was finished they stayed to farm or work in the local quarries. In the 1890s the sanitary canal, the waterway that reversed the flow of the Chicago River, brought more Irish to Sag Bridge and Lemont, as well as the Bridgeport neighborhood of Chicago. The colorful history includes many prizefights that were held in Sag Bridge around the turn of the 19th century. The fights were staged there because “the Sag” was easily accessible by canal barge from Bridgeport.
What does “Sag” mean, and what was the bridge? The answers are speculative, just as the history is murky. The term Sag probably derived from a Potawatomi Indian word, Saginaw, which may have meant “swamp”. The Sag Valley was a low-lying swampy area, and it is presumed that a bridge may have provided transport across it. The name could also refer to the geographic coming together of the two valleys. When one considers that recorded history relates that the first white settlers to arrive in the area came in 1833, and that the oldest grave at Saint James Cemetery is that of Michael Dillon, buried in 1816, further fuel is added to doubts about the accuracy of the history.