The Shepaug, Litchfield and Northern Railroad (The"Shepaug" name derives from the Shepaug River that most of the line followed which in turn was a Mohegan name that meant "rocky water".) was a short independent railroad in western Connecticut that was chartered as the Shepaug Valley Railroad in 1868 and operated from 1872 to 1891 when it was taken over by the Housatonic Railroad. In turn, in 1898 the Housatonic operation of the line was in turn taken over by the New York, New Haven and Hartford Railroad (NYNH&H). The line was abandoned in 1948. However much of the line remains in place as rail trails to this day. Henry R. Colt, the gun manufacturer, was the lines original treasurer.
Gail Borden's condensed milk business had started operation in the Burrville section of Torrington in the 1860s and thanks to strong sales during the civil war the milk business was profitable, a new Borden creamery was built and started shipping dairy products out of Washington Depot soon after the start of operations on the SL&N began.
The need to get milk as fresh as possible to New York City markets led to runs of a Sunday "milk train". At first the milk was delivered to Hawleyville to be picked up by the Housatonic and then carried to Bridgeport and on to New York. Eventually the creamery at Hawleyville was closed as was the Hawleyville branch, by which time the milk train ran through Danbury to South Norwalk.
Other significant freight shippers included stone quarries near Roxbury and New Preston (marble and granite) and ice cut from Bantam Lake.