The Chesapeake and Ohio was among the first railroads to test the 4-6-2 wheel arangement (around 1902) and had at least one 4-6-2 before the Missouri Pacific (from which the wheel arrangement gots its name). The C&O originaly called the 4-6-2s "Mountains", but the name did not stick. Their official name on the C&O was "Ten Wheeler with trailer".

The F-19 class of C&O Pacifics were the only Pacifics to be delivered new with Elesco feedwater heaters, flying (smokebox-mounted) airpumps, and deck-mounted headlights. They all were equiped with vanderbuilt tenders which carried the large C&O logo on the coal bunker sides.

These locomotives became the standard power for the George Washington (a night sleeper train) on most of the route between Washington and Newport News to Chicago. The F-19 class was considered to be the manifestation of the Georgian steam locomotive and was generally believd to be the prettiest locomotives the C&O ever owned.

In 1946 and 1947 they were rebuilt into streamlined class L-1 4-6-4 Hudsons (the road numbers remained the same). One, number 490 still survives at the B&O Railroad Museum.