Through mergers and new construction, the railroad, named Chicago Great Western after 1892, quickly became a multi-state carrier.

Stickney,[2] it had established routes west to Omaha, Nebraska, south to St. Joseph, Missouri, and east to Chicago, Illinois, via the Winston Tunnel near Dubuque.

In 1892 the city of Oelwein, Iowa was chosen as the headquarters and primary shop site due to its central location on the mainline.

The two-story combination machine, boiler, and coach shop alone measured 700 feet (213 meters) long and had 27 pits for overhauling locomotives.

[4] In 1910, the CGW introduced four McKeen Motor Car Company self-propelled railcars, its first rolling stock powered by internal combustion engines.

During the 1920s, as ownership changed again to the Bremo Corporation, a group of investors led by Patrick Joyce, an executive at the Standard Steel Car Company,[4] the railroad expanded its use of self-propelled vehicles.

[6] In 1949, William N. Deramus III assumed the presidency, and began a program of rebuilding infrastructure and increasing efficiency, both by consolidating operations such as dispatching and accounting and by lengthening trains.

[13] Testifying in 1965, before the Interstate Commerce Commission in Chicago, President Reidy statedthat although it was operating in the black it would not be able to continue: The simple fact is that there is just too much transportation available between the principal cities we serve.

Despite the railroad's small size and meager passenger fleet, it looked for ways to more efficiently move passengers, such as employing all-electric (battery powered)[7] and gas-electric motorcars on light branch lines, which were cheaper to operate than traditional steam or diesel-powered trains.