Founded in 1901 by the merger of eight manufacturers, the American Locomotive Company eventually became the second largest in the United States, behind Baldwin. ALCO built over 75,000 engines, including some of the largest ever constructed, the ¿Big Boy¿ 4-8-8-4s created for the Union Pacific. Originally published in 1908, this 40-page pamphlet is illustrated with photos and diagrams. It includes text written by C.J. Mellin, the Chief Engineer of the Richmond Works and holder of a number of patents related to the articulated compound locomotive. This innovative design spread the locomotive¿s weight across multiple driving wheels of a relatively small diameter. As a result, engines of this type could operate on short-radius curves, while still providing enormous traction power