Construction began on April 23, 1852, and the full line opened May 9, 1853, from Palmer north to Amherst via Belchertown and Dwight.

It went bankrupt in 1857, was sold at auction on October 14, 1858, and was reorganized on November 23 of that year as the Amherst, Belchertown and Palmer Railroad.

On December 1, 1871, the Central Vermont Railroad leased the New London Northern and made it its Southern Division.

Just prior to that lease, in February, the 3 ft (914 mm) narrow gauge Brattleboro and Whitehall Railroad was leased, providing a branch from Brattleboro northwest to a dead end at South Londonderry (never extended as planned to Whitehall, New York).

The West River Railroad was chartered in May of that year as a reorganization, and the line was converted to 4 ft 8+1⁄2 in (1,435 mm) standard gauge.

The CV continued passenger service on the Brattleboro - Amherst - Palmer - Norwich - New London route until September 27, 1947.

The Mansfield stop provided the nearest point of rail access to the University of Connecticut at Storrs.