Here's a 'companion' film to the New Haven in film.
The Boston and Maine started in the 1830s and eventually controlled nearly all of the rail lines in northern Massachusetts and nearly all of those in New Hampshire. The railroad was friendly with the Maine Central and for many years partnered together and even shared equipment on passenger trains. They were friendly rivals of the New Haven with the New Haven having all of southern Massachusetts and all of Connecticut and Rhode Island. The B&M did, however, have a nemesis, and that was the Boston and Albany a railroad controlled and wholly-owned by the New York Central.
In the 1910s, JP Morgan gained control of the B&M and New Haven. While this gave both roads cash, and allowed the B&M to electrify the Hoosac Tunnel, the cash influx was short-lived. The New Haven and Boston and Maine had plans to expand their routes and electrify core main lines including the routes from Boston to East Deerfield where the two lines crossed and the former Eastern Railroad from Boston to Portsmouth. As we know, this never occurred.
JP Morgan pulled out cash from both New Haven and Boston and Maine to prevent himself from going bankrupt during the Panic of 1916. This forced both roads into bankruptcy which led to trimming of branch lines and some major lines. During the boom times, the B&M purchased the Worcester, Nashua, Rochester, and Portland mostly to kill it due to the competition and this line all but disappeared in the 1920s during the restructuring and the B&M was out of bankruptcy in 1923 only to face the Depression and then Patrick McGuiness in the mid-1950s to early 60s. The Depression and post WW II saw more branch lines trimmed, mostly due to lack of service and lack of cash, and McGuinness did his part in trimming more.
Under McGuiness's control, the road faced cuts in passenger service and a reduction in freight operations much like what occurred on his New Haven, and ended up bankrupt again. McGuiness went to prison after scrapping and selling their turbo train and pocketing the cash.
After trimming more lines and selling off assets, the B&M emerged from bankruptcy in the early 1980s only to be purchased outright by Guilford Transportation Industries. Guilford was formed by stakeholders in the Maine Central. Guilford, however, was not interested in running railroads and only saw the combined MEC and B&M operations as real estate to sell off. The company focused on through routes only and all but eliminated all branch line feeder lines all while selling off ROW and land to developers. In 2022, Guilford, now renamed Pan Am Railways, sold itself to CSX. CSX is currently rebuilding both the MEC and B&M.