The first steam locomotive in North America fitted with the Walschaerts valve gear was the "William Mason", built in 1874 by the Mason Locomotive Works for the Boston, Clinton, and Fitchburg Railroad (which later became part of the New York, New Haven, and Hartford Railroad.) The venerable John H. White refers to the locomotive as being a "Mason-Fairlie" type locomotive in his book "A History of the American Locomotive: Its Development, 1830-1880", while some random guy who wrote a Wikipedia article refers to it as a "Mason Bogie."