The Chicago & North Western Railway can trace its roots back to 1836, when the Galena and Chicago Union Railway charted a line across the northern part of Illinois, to connect the namesake cities. This railroad formed up and began operations in 1848, and reached Freeport, Illinois by 1853. The railroad never reached Galena because Illinois Central built along the route first. At the same time, a branch line from Belvidere, Illinois to Beloit, Wisconsin would be completed. The Chicago and Galena Union Railway also built a branch to Dixon from Turner Junction (West Chicago). This branch would be completed in 1855, and the Mississippi and Rock River Railway would finish it in 1855, to the Mississippi River at Fulton, Illinois.
The Chicago, St. Paul and Fond Du Lac Railroad began building a major line in 1855, from Cary, Illinois to Janesville, Wisconsin. At Cary, it connected to a significant line from Chicago built by the Illinois and Wisconsin Railway, built the year prior. The Chicago and North Western Railway constructed their first pieces of tracks in 1859, on a line charted by the Chicago, St. Paul and Fond Du Lac Railroad in 1857. This line was constructed from Janesville to Green Bay (Fort Howard) from 1859 to 1862.
In 1864, the Chicago & North Western Railway would take over operations of the Galena and Chicago Union Railway. William B. Ogden became the first president of the company.
The final of the major charting railroads was the Winona & St. Peter Railroad, which constructed significant line from Winona, Minnesota to Brookings, South Dakota between 1867 and 1873. This railroad became a part of the Chicago & North Western Railway in 1867, and was operated by the C&NW.
Between 1870 and 1900, the Chicago & North Western Railway saw massive change, as the empire grew to Minnesota. It began to take a controlling stock in the Chicago, St. Paul Minneapolis & Omaha Railway, which constructed a mainline from Elroy, Wisconsin to Sioux City, Iowa. Additional mainlines constructed included St. Paul to Chicago, via Milwaukee; as well as Madison to Chicago via Janesville. Other significant lines were the Chicago to Omaha via Clinton, Iowa and Ames, Iowa line; the Janesville to Green Bay line, and Eau Claire, Wisconsin to Superior, Wisconsin.
Throughout the next several years, legendary president Marvin Hughitt was at the helm. He heavily advocated for construction of new lines, double tracking of existing lines and purchase of smaller railroads.
A major project was undertaken while he was in charge, which included the double tracking of the entire Chicago to Omaha Route, including construction of a new massive bridge at Boone, Iowa.
When Hughitt retired in 1910, the railroad was preparing for the largest capacity expansion ever. This would include a new mainline from Sparta, Wisconsin to Chicago, taking a direct route through Milwaukee. In
addition, the entire line between St. Paul and Wyeville would be double tracked. Significant new trackage would be added in Milwaukee and Chicago. In addition, a line would be constructed between Peoria and St. Louis to haul coal from Central Illinois.
Map above credit of the Chicago & North Western Historical Society. Note that several lines were not yet complete in 1909, at the time of the map.
While many entities struggled during the 1930s, the C&NW remained rather prosperous. This lead to the purchase of the Minneapolis & St. Louis Railway in 1960. An additional purchase in 1968 secured the Chicago Great Western Railway. Both these railroads would be significantly gutted by the time C&NW was purchased in 1995. The death of the Chicago, Rock Island & Pacific also helped spell the death of the two acquired railroads. In 1983, the Chicago & North Western picked up several lines of the Rock Island and rebuilt them.
By the end, the Northwestern left a winner. The Union Pacific Railroad purchased the Northwestern, and still operates significant parts of it.
Examples of Chicago & North Western Bridges can be seen above.