An expansion attempt southeastward from Woodlawn to the Seekonk River was launched in the first decade of the 20th century, but was abandoned in 1913 following opposition from the New Haven.

A self-propelled steam dummy with passenger accommodations made up to 13 round trips per day on the line, which included three full stations and a further five flag stops.

The Boston Globe wrote in 1903 that "There is no combination car and locomotive like the one on the Moshassuck in use in any part of this country, it is believed by the operators of this one.

[6] In the early 1900s, the Moshassuck Valley Railroad launched an attempt to extend its line from Woodlawn to the Seekonk River, enabling the company to exchange cargo with ships and directly compete with the New Haven.

[9] The New Haven stated it had no objections to the expansion in principle, and would be satisfied if the extension crossed over the area of the yard on a bridge, which would need to be 200 to 300 feet in length.

[10] The Moshassuck Valley Railroad abandoned its plans to build the extension in December 1913, with newspapers speculating that this was either because the company believed the Southern New England Railway (then under construction) would allow another connection to the river, or because the company was confident in its ability to maintain good relations with the New Haven Railroad.

P&W cut back the northernmost three-quarters of a mile (1.21 km) of the line in 1991, while the remaining portion continues to serve a local industry as of 2022.