Union Pacific Big Boys from Kalmbach covers the who, what, why, and when of UP′s 25 popular 4-8-8-4 steam locomotives. This book gives the historical background on their early 1940s development, explains why they were built, how they were used, and traces their history until they were retired around 1960 as well as the restoration and operation of #4014 beginning in 2013. Union Pacific Big Boys is one of several Kalmbach products highlighting the Union Pacific Big Boy. Hardcover, 224 pages.