Northern Pacific steam locomotive 5100 at Schenectady, New York in 1936. Number 5100 is a class Z-6 built by Alco-Schenectady in 1936. Photo by AH Fiedler, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 4008 posed for a builder's photo in April 1913. Number 4008 is a class Z-3 built by Alco-Schenectady in 1913. Photo by Alco-Schenectady, J.M. Fredrickson collection. Other Subject Classes: steam locomotive in roster photo

Northern Pacific steam locomotive 3 at Schenectady, New York, in 1897. The builder's photo of Number 3, (later number 13), a class X, was built by Schenectady as a compound for helper service in 1897. Photo by Schenectady Loco. Works, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, builder's photo

Northern Pacific steam locomotive 2446 posed for a builder's photo at Dunkirk, New York, in 1907. Number 2446 is a class T built by Alco-Brooks in 1907. J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Builder's photo of Colorado Midland steam locomotive number 23, built for passenger service at Schenectady Locomotive Works in Schenectady, New York, in 1887. Photo from J.M. Fredrickson Collection. Other Subject Classes: steam locomotive, builder's photo