The original vestige of what eventually became the Boston and Maine Railroad's Portsmouth Branch started out as the Portsmouth and Concord Railroad in 1848, which constructed a railroad line between Portsmouth and Candia, in New Hampshire. The remainder of the line into Concord, via Suncook, was completed three years later. Financially troubled from the beginning, the P&C went into receivership and emerged as the Concord and Portsmouth Railroad in 1855, and operations over the route continued.
A mere three years later, in 1858, the entire line came under the control of the Concord and Montreal Railroad, who leased the line to the Concord Railroad in 1861. As part of this lease agreement, the Concord Railroad built two branch lines in order to connect this route with its own mainline on the west side of the Merrimack River:
- A branch line between the P&C in Candia and the Concord RR in Manchster, abandoned by the Boston and Maine Railroad in 1982
- A second branch line between the Concord RR in Hooksett and the P&C in Suncook, crossing over the Merrimack River, abandoned in 1943
These two branch lines effectively made obsolete the segment of line between Candia and Suncook, which was subsequently abandoned that same year.
The Boston and Maine Railroad took control of the entire line in 1944, after having leased it since 1895. A bridge washout over the Merrimack River, just south of Concord, forced the abandonment of the Concord-Suncook segment (and along with it the Suncook Valley Railroad). The B&M continued operating the line from Portsmouth into Manchester via Candia, known as the Portsmouth Branch, until 1982, when it abandoned that portion of the line west of Rockingham Junction.
A rough timeline of this route, along with its two connecting branches:
Concord Suncook Candia Rockingham Jct Portsmouth
=======================================================================
1849 |-- Portsmouth & Concord RR --|
1852 |------ P&C RR -------|
1855 |------------ Concord & Portsmouth RR --------------|
1858 |------------- Concord & Montreal RR ---------------|
1861 |--- CRR --|..........|-------- Concord RR ---------|
1944 |--- B&M --| |----- Boston & Maine RR -----|
1952 |..........| |----------- B&M -------------|
1982 |..............|---- B&M -----|
Suncook Hooksett | Manchester Candia
========================== | ===========================
1861 |--- CRR ---| | 1861 |---- CRR ----|
1943 |...........| | 1944 |--- B&M RR --|
| 1982 |.............|
|.....| = abandonment of line
Today, the line between Rockingham Junction and Portsmouth is still in use by the B&M (now a Pan Am Railways subsidiary). A portion of the right-of-way also serves as the Rockingham Recreational Trail. Surprisingly, the earliest abandoned segment of this route, between Suncook and Candia, abandoned in 1861, can still be seen in satellite imagery.
