The classifications given by railroads to their steam locomotive fleets were as varied as the machines themselves with several different designations within a particular class! As for the Lehigh and Hudson River Railway steam locomotives there were not many (a little over 60 ever owned) since the railroad was rather small. However, the L&HR did own some some rather large steamers for its size, small fleets of 4-8-2 Mountains and 2-8-2 Mikados. Today, none of the railroad's largest steamers are known to exist and sadly, none at all are known to be preserved.
In any event, the information here is merely meant to list the general types of steam locomotives operated by the L&HR and does not go into detail about their specific differences. A few additional points about the L&HR's steam fleet: first was that its entire fleet was built by the Baldwin Locomotive Works; second was that the railroad in later years rebuilt some of its 4-4-0 Americans, 2-6-0 Moguls, and 2-8-0 Consolidations into Camelbacks (whereby the cab was moved to the center of the boiler to allow for the Wootten firebox, a patented design that allowed for the use of anthracite coal waste, known as culm, to be used as a fuel source for locomotives), which are listed below.
4-4-0 Americans #1 - 7: Built by Baldwin Locomotive Works.
4-4-0 Camelback #8: Built by Baldwin Locomotive Works.
2-6-0 Camelback #9: Built by Baldwin Locomotive Works.
2-8-0 Camelback #10 - 12 (Original): Built by Baldwin Locomotive Works.
4-8-2 Mountain #10 - 12 (Renumbered): Built by Baldwin Locomotive Works.
0-6-0 Switcher #15 (Renumbered): Built by Baldwin Locomotive Works.
4-6-0 Ten-Wheeler #20: Built by Baldwin Locomotive Works.
4-6-0 Camelback #23 - 34: Built by Baldwin Locomotive Works.
2-8-0 Camelback #50 - 69: Built by Baldwin Locomotive Works.
2-8-2 Mikados #70 - 73, #80 - 83: Built by Baldwin Locomotive Works.
2-8-0 Consolidation #90 - 95: Built by Baldwin Locomotive Works.
For more reading about steam locomotives like those operated by the L&HR consider Perfecting the American Steam Locomotive by author J. Parker Lamb. As the name implies the book details the earliest history of steam engine technology, even before it was used in railroad applications. His book later explores the development of steam locomotive technology in the United States from the 19th through the 20th centuries, covering not only the most popular steam locomotive designs but also the most successful manufactures to build them. The book has received excellent reviews and is a great resource on steam locomotives and a fine reference tool; you should find it very useful.
Also, consider the book American Steam Locomotives from author Brian Solomon. While this publication does not include quite as much technical data as Lamb's book, Perfecting the American Steam Locomotive, it is still a very good resource with lots of information and best of all, is loaded with photographs! If you're interested in perhaps purchasing either (or both) of these books please visit the links below which will take you to ordering information through Amazon.com, the trusted online shopping network.