The Hudson came into being because the existing 4-6-2 Pacific power was not able to keep up with the demands of longer, heavier trains and higher speeds. The existing 4-6-2 design was modified with a bigger boiler and firebox, and a modified Berkshire-type trailing truck, creating a revolutionary class of locomotive that inspired other railroads to build their own 'Hudsons'. Indeed, the Milwaukee Road was the first to design its 4-6-4's - known at first as the 'Milwaukee' type in the planning stages, but later known as the 'Baltic' type - but not the first to be built as the Milwaukee was still short on money. These engines are named after a river that was 315-miles long and flows from north to south primarily through eastern New York in the United States - the Hudson River. Locomotive No. 5200 was the very first Hudson built for the New York Central and took to the rails in 1927.
These engines are used for high-speed passenger train work, the Hudson locomotives were famously known for hauling the New York Central's crack passenger trains, such as the 20th Century Limited and the Empire State Express. When these services were being re-equipped, the train engines had to be given some changes. In Autumn 1941, two Hudsons - 5426 and 5429 - were streamlined by Dreyfuss specially for the Empire State Express, and were painted black but mostly clad in silver. The newly-streamlined train was launched, rather soberingly, on the same day the Japanese bombed Pearl Harbor - December the 7th, 1941. Soon afterwards, the US declared war on Japan, and joined World War Two.
In 1944, NYC received permission from the War Production Board to build a new, high-speed locomotive of the 4-8-4 type, combining all the advantages of the Hudson with those of the Mohawk.
All the Hudsons were retired by the late 1950's with the onset of diesel locomotives in the mid-20th century.
No Hudsons have been preserved, though an engine of the same wheel arrangement with a look similar to that of the NYC Hudsons - Nickel Plate Road No. 170 - survives.
- There are 3 different Hudson classes: J-1, J-2 (for the Boston and Albany) and J-3.
- There are also 5 different sub-classes for the J-1 series: J-1As, J-1Bs, J-1Cs, J-1Ds, And J-1Es.
- The Dreyfuss 'Century' Hudsons featured the nose of the smoke box that looked like a spaceship with the fin on it.
- Locomotive #5344 had streamlining briefly applied and named "Commodore Vanderbilt". The Commodore Vanderbilt was among the first streamlined steamers on the New York Central, if not the world. The streamlining was later replaced to match the last ten J-3a locomotives that had been built with streamlining designed by Henry Dreyfuss.
- The character Connor from Thomas & Friends is stylized after a streamlined NYC Hudson.
- A J-1d Hudson was once originally numbered 6615 and it was later renumbered 5390. It was built for the Big Four Railway, hence its original number.
- However, since the Peppercorn A1 60163 Tornado was completed in the UK in 2008, some volunteers known as The Hudson Steam Locomotive Revival Project (HPR) are seeking to build a fully operable replica of a New York Central J-3a Hudson to be numbered 5475 in Buffalo, New York.