- 1854: 39 miles completed from Chicago to Cary, Illinois by the Illinois & Wisconsin Railroad
- 1855: I&W combined with Rock River Valley Union Railroad to form the Chicago, St. Paul and Fond du Lac Railroad
- 1855: 53 miles completed from Cary to Janesville, Wisconsin by the Chicago, St. Paul and Fond du Lac Railroad
- 1859: CStP&FdL sold to Chicago & North Western Railway
- 1882: Second track completed from Chicago to Mayfair (Montrose Avenue)
- 1884: Second track completed from Mayfair to Des Plaines
- 1886: 16 miles completed from Janesville to Evansville, Wisconsin by the Janesville and Evansville Railway
- 1887: J&E sold to the Chicago & North Western Railway
- 1893: Second track completed from Des Plaines to Barrington
- 1899: Second track completed from Barrington to west of Harvard, Illinois
- 1899: Second track completed from Shopiere to west of Janesville, Wisconsin
- 1899: Track elevation completed from Kostner Avenue to Sangamon Street in Chicago
- 1908: Second track completed at Rock River in Janesville, Wisconsin
- 1927: Track elevation completed from Kostner Avenue to Foster Avenue in Chicago
- 1995: Chicago & North Western purchased by Union Pacific Railroad
- 1984-Present: Metra operates the Union Pacific Northwest Line between Harvard and Chicago
- 1995-Present: Union Pacific operates the Harvard Subdivision from Chicago to Evansville, Wisconsin
07/17/21
Located in Woodstock, this highly significant stone arch bridge crosses South Street.
Originally built in 1867, the bridge is a highly rare example of a helicoidal stone arch. A helicoidal stone arch has a twist in it, and is considerably more difficult to construct than a regular stone arch.
A second track was added in 1897, by simply combining with the original span.
Apart from the age, the helicoidal design is among the rarest types of bridges in the United States. Also known as a spiral arch, only nine are known to exist in the US. Two exist in Illinois.
The age is also cause for significance. An 1860s bridge is a feat, especially when considering the arch design.
Overall, the bridge appears to be in good condition.
The author has ranked this bridge as being nationally significant, due to the unique design and exceptionally old age.
The photo above is a view of the west (1897) face.