The oldest part of the Rockland Branch is the section between
Brunswick, Maine, and
Bath, Maine. This was built in 1849 by the
Kennebec and Portland Railroad, as part of a line that was later extended to
Portland, Maine. The
Knox and Lincoln Railroad was chartered that same year to build east from Bath to
Rockland, Maine. The line opened between
Woolwich, Maine, across the
Kennebec River from Bath, and Rockland on October 31, 1871. A
train ferry connected Bath and Woolwich. The
Maine Central Railroad acquired the
Portland and Kennebec Railroad, successor to the Kennebec and Portland Railroad, in 1874. After several overtures, it leased the Knox and Lincoln Railroad in 1891 and acquired it outright in 1901. Under Maine Central control, the line between Brunswick and Rockland became known as the Rockland Branch. The Maine Central purchased the Samoset
destination hotel in Rockland in 1911, and offered direct passenger service for summer visitors from the large eastern cities. The completion of the
Carlton Bridge over the Kennebec River in 1927 finally created an all-rail route to Rockland. The Maine Central sold the Samoset hotel in 1941 and discontinued passenger service to Rockland on April 4, 1959. The Maine Central itself became a subsidiary of
Guilford Transportation Industries in 1981. The state of Maine acquired the branch between Bath and Rockland in 1987. The
Maine Coast Railroad began freight service over the branch on October 26, 1990. The state acquired the remaining part of the branch between Brunswick and Bath on February 26, 1991. The Maine Coast Railroad ended service on December 4, 2000.
Safe Handling Rail took over as interim operator of the line. The state selected the
Morristown and Erie Railway as the new operator in October 2003, who in turn incorporated the
Maine Eastern Railroad. The
Central Maine and Quebec Railway replaced the Maine Eastern as the operator in 2016. In 2019,
Canadian Pacific Railway agreed to purchase the Central Maine and Quebec, thereby inheriting the operation of the Rockland Branch. The acquisition was completed on June 3, 2020, and the Canadian Pacific took over as operator. The
Finger Lakes Railway subsidiary
Midcoast Railservice succeeded the Canadian Pacific on August 1, 2022. On August 16, 2024, Midcoast Railservice filed a petition to discontinue service on the line. This is due to the closure of their main customer, Dragon Cement, closed their plant on the line. According to Midcoast, the line was operating at a loss, generating only 5 cars per month. The
Cumberland and Knox Railroad began operations on May 31, 2025. ==Notes==