The line was completed December 21, 1871; the previous month the company had leased the easternmost section of the D&C to gain access to the New York & Harlem Railroad at Millerton.

Over the years, several plans had been made for a fixed span across the Hudson River south of Albany to replace the numerous car float operations.

The connections were not completed until 1889, and on July 22 the two approaches merged to form the Central New England & Western Railroad.

The two companies merged on August 1, 1892 to form the Philadelphia, Reading & New England Railroad (PR&NE).

Less than six months after the Springfield extension debuted via the loop, the Montague property was suddenly obtainable for a pittance.

NH acquired financial control of CNE that same year, mostly for the Poughkeepsie Bridge and western connection at Maybrook that it would soon develop to its fullest potential.

In 1910 the Poughkeepsie & Connecticut main line was abandoned in favor of the parallel Poughkeepsie & Eastern Railway from Pine Plains, New York, southwest to Salt Point, where the two lines had crossed The P&E used trackage of the Newburgh, Dutchess & Connecticut Railroad (also merged into the CNE in 1907) from Pine Plains southwest to Stissing, NY.

The New Haven ended all passenger service on the CNE lines that year, with the exception of the segment running from Copake, New York, southwest to Stanfordville, Pleasant Valley and Poughkeepsie, which ran at least to January, 1932.

In 1932 the former Rhinebeck & Connecticut Railroad was abandoned from Copake (northwest of Boston Corners) southeast to the state line, cutting the CNE in two.

The NH had removed CNE tracks from Waterbury west to Southbury in 1937, a critical link in any east-west rail itinerary between the mid-Hudson Valley (Campbell Hall and Poughkeepsie) and eastern Connecticut (Willimantic).

At the time of the 1969 merger of the NH into Penn Central, all that remained of the original CNE was the westernmost section, from Maybrook over the Poughkeepsie Bridge and southeast along the Dutchess County Railroad to the former NY&NE as well as the easternmost portion to the northern part of Bloomfield, CT, from Hartford.

The westernmost section was part of the Maybrook Branch, continuing east over former NY&NE and other lines to Derby.

The Connecticut Department of Transportation later acquired it and in January 1999 the Central New England Railroad began operations on the 8.7 mile (14 km) Griffins Industrial Track.