Which railroad introduced the Hudson steam locomotive type in North America?

The New York Central Railroad introduced the Hudson steam locomotive type in North America.

New York Central developed the design in the 1920s as its Pacific locomotives struggled with longer, heavier passenger trains. Chief mechanical engineer Paul W. Kiefer adapted the high-capacity firebox concept associated with Berkshire locomotives to a 4-6-4 layout, adding a four-wheel trailing truck to support the enlarged firebox.

The first prototype, No. 5200, was built by the American Locomotive Company in 1927 to New York Central's design. The railroad named the new type Hudson after the Hudson River, which runs through the railroad's home region and past New York City.

The type became strongly associated with premier passenger trains such as the 20th Century Limited and Empire State Express. Other railroads later built their own Hudsons, including Canadian Pacific, Milwaukee Road, Burlington Route, and New Haven, but New York Central was the North American pioneer. Its system and subsidiaries eventually operated 275 Hudsons.