The 6755 was built by the Altoona Works in 1930. The 6755 was a class M1a and was used predominantly in freight service, though it would occasionally be used for passenger trains. In 1953, the locomotive went back to the Altoona Works and was rebuilt into a class M1b. The locomotive continued to be used for freight service until January 1957 when it was retired from the roster. Today, the 6755 is on static display at the Railroad Museum of Pennsylvania in Strasburg, Pennsylvania. The 6755 has since been deteriorating at a rapid pace, with its boiler jackets removed in the early 2000s prolonged exposure to the elements has wreaked havok on major parts of the locomotive causing structural rust. To date no plans have been made to bring 6755 indoors from the elements.