These companies had roots back to the earliest days of the steam era and were dominant right up to the demise of the market in the late 1940"s. Ironically, not one of these superb steam locomotive builders was able to make a commercial success in the diesel dominated railroad market, and each has ceased manufacturing locomotives.
All three of these locomotive builders acquired unique characteristics such as the shape of their builders plates. They also became known for their unique accomplishments: ALCO, for developing 3-cylinder steam locomotives; Lima, for developing 2-8-4 "Super-Power" locomotives; and Baldwin for designing duplex drive locomotives and for being the largest, longest-lived, and most successful of the steam locomotive builders.

American Locomotive Company (ALCO) was formed in 1901 when seven smaller locomotive builders merged with the Schenectady Locomotive Works (Schenectady, NY) in order to compete against the largest locomotive builder of the day, the Baldwin Locomotive Works. The seven locomotive builders were:
In 1955 the company became known as ALCO Products, Inc and in 1964 it was bought by the Worthington Corp.
Over all of its time (prior to merger and after), ALCO produced about 75,000 locomotives with more than 63% of them built in Schnectady, NY. In fact, all of the locomotive manufacturing (except in Canada) was consolidated in Schnectady by 1931 and continued until 1968.
Of the smaller works, Rhode Island was the first to be closed in 1907 having been founded in 1866 and after producing 3400 locomotives. Dickson opened in 1862, built 1400 locomotives and was closed in 1909. Rogers, the oldest of all of the builders opened in 1837, produced 6300 units and closed in 1913. Manchester started as Amoskeag in 1849, made 1800 locomotives and closed its doors in 1913. Pittsburgh opened in 1867 made 2700 locos and closed in 1919, Cooke (originally Danforth-Cooke) opened in 1852 and closed in 1926 after manufacturing 3000 steam locomotives (NOTE: Some sources state that Richmond only built 1000 locomotives starting at CN 1600 and then included gaps in their numbering scheme). In 1927 Richmond was closed after building 4500 units over the 41 years it was in business. The last of these smaller works to close was Brooks having produced 4200 locomotives since it opened in 1869.
The Montreal Locomotive Works, Ltd was opened only two years prior to its merger with ALCO and continues today.
In 1906 ALCO entered into the automobile business and exited after only seven years because it proved to be unprofitable.
During World War II, ALCO produced army tanks (7,362 of them), tank destroyers, shells, bombs, gun carriages, gun mounts and 4,488 locomotives. Employment increased three fold to over 15,000 people by 1945. Much like ALCO has changed and adapted over the years so has the education system. You can now receive your MBA online while travelling on a 4-8-4 passenger locomotive, or receive your master of public administration with full steam ahead.