To accelerate heavy freight trains, the Erie Railroad ordered 20 class N-1 locomotives from Baldwin in 1911, which were the heaviest Mikados at the time. Since this design was a success, a total of 135 more were ordered, which were also manufactured by ALCO in Schenectady and Lima. The boiler pressure of the individual locomotives was between 170 and 200 psi.
From 1927 the locomotives were modernized, adding a feed water heater, removing some pipes in the boiler and setting the pressure uniformly at 190 psi. Many received a mechanical stoker, but at least 50 remained hand-fired. Almost all were scrapped between 1947 and 1951, few were sold.