In February 1851, the Illinois Legislature incorporated the Illinois Parallel Railroad Company, giving it the power to lay tracks north from Chicago along the shore of Lake Michigan to Waukegan and then to the Wisconsin state line. The line was soon renamed the Chicago & Milwaukee Railroad and the route it took would evolve into today’s UP North Line.

A month later, the Wisconsin Legislature authorized the Green Bay, Milwaukee & Chicago Railroad Company to build several routes, including one from Milwaukee south to Racine and Kenosha and then to the Illinois state line.

The Chicago & Milwaukee reached Waukegan in 1854, and passenger service began immediately. The railroad soon reached the state line, where it linked up with the Wisconsin railroad to connect Chicago and Milwaukee (for a short time passengers and freight traveling between the two cities had to change trains at the state line).

The meeting of the railroads was celebrated by Chicagoans and Milwaukeeans during a major “last spike” ceremony in Kenosha in 1855. Among the dignitaries was Illinois Senator Stephen Douglas, who delivered a speech, "taking as his subject the manifest destiny of the Northwest to become the dominant section of the entire country. Chicago was to be the greatest city on the continent and Milwaukee was to be a close second.” That quote is from a history of the Chicago & North Western Railroad, which started leasing the Chicago & Milwaukee in 1866 and bought it outright in 1883.

In 1857, the Wisconsin half of the line was renamed the Milwaukee & Chicago Railroad. Six years later the Chicago & Milwaukee and the Milwaukee & Chicago joined forces, with the moniker Chicago & Milwaukee Railroad winning out as the name for the combined operation.

A local train for North Shore residents began in 1856. Early commuter service was so unprofitable that the directors of the railroad nearly gave up to concentrate on freight. But the superintendent convinced them to give the commuter trains more time for business to pick up. Eventually it did – and one of the beneficiaries was the railroad’s president, Walter Gurnee, a former Chicago mayor who with his partners did well buying up and selling land around stations in what would become Lake Bluff, Highland Park, Ravinia, Glencoe and Winnetka. (The far north suburban village of Gurnee is named after him, but he never lived there and may not have ever set foot in the area.)

In 1869, service between Chicago and Kenosha consisted of seven trains each way daily. Downtown, most of those trains terminated at a station at Wells and Kinzie that had been built in 1853. The trip from Kenosha, making stops in Waukegan, Rockland (Lake Bluff), Lake Forest, Highland Park, Glencoe, Winnetka, Evanston, Calvary (cemetery), Rosehill (cemetery) and Ravenswood, took about two hours and 10 minutes.

The Great Fire of 1871 destroyed the downtown depot and it took 10 years to build a new one at the same location. During that decade many suburbs grew quickly, in part because the fire increased the desirability of living away from the congested city but also due to economic and demographic trends that contributed to the growth of all suburbs. Commuter service grew accordingly.

As David Young notes in "The Iron Horse and the Windy City," Evanston was the only incorporated town along the line in 1870, “but within a decade there were six suburbs with a combined population of 11,833, and by 1900 the combined population of the corridor had quadrupled.”

In 1896, work began to elevate the C&NW tracks on the north side of Chicago to comply with a city ordinance aimed at eliminating grade crossing accidents. (Evanston later passed a similar ordinance.) The bridges that were built over city streets back then are the ones now being replaced in Metra’s UP North bridge replacement project.

In 1906, land acquisition began for a new passenger terminal in Chicago at the site where Ogilvie now is located. Work began in 1908 and the facility was completed in 1911.

When the terminal opened, the headhouse featured an immense waiting room with a three-story barrel-vaulted skylight, as well as dressing rooms, baths, nurses and matrons rooms, and a doctor’s office. Tracks were on the second level, above a mail substation and other facilities.

The head house was razed in 1984 to make way for the 42-story Accenture Tower, which was completed in 1987. The second-level platforms survive as part of Ogilvie.

Most of this information is from a history of the C&NW that was issued by the railroad in 1910; "The Iron Horse and the Windy City" by David M. Young; and "Forty Years on the Rail" by Charles B. George. Metra timetables for the UP North are “Flambeau Green”; green for the C&NW’s historical green and yellow locomotives and Flambeau for one of its passenger trains.