Built at the close of the nineteenth century, the structure incorporates many features of the Richardsonian Romanesque architectural style.

[4] On December 29, 2014, Amtrak's Vermonter began stopping at a new passenger rail boarding platform located just to the south of the Union Station building.

The Connecticut River Railroad opened to passenger service between Springfield and Northampton in late 1845; trains reached Deerfield in August 1846, Greenfield in December 1847, and the junction with the Central Vermont Railway in January 1849.

[6] In 1972, Amtrak began running the Montrealer, which ran along the line at night, stopping at Northampton but not Holyoke or Greenfield.

Montrealer service resumed in 1989 after Amtrak seized control of the line in Vermont from the Boston and Maine Railroad, but the train was rerouted over the Central Vermont Railway through Massachusetts and Connecticut to avoid the still-dilapidated Conn River Line which Amtrak did not control.

[4] In order to shorten travel times on the Vermonter and add additional local service to serve the populated Connecticut River Valley, the Conn River Line was rebuilt with $73 million in federal American Recovery and Reinvestment Act money and $10 million in state funds.

[18] On August 30, 2019, Amtrak extended two daily Amtrak-operated Hartford Line round trips (branded as the Valley Flyer) to Greenfield as a pilot program.