This abandoned line started out as the New Castle and Franklin Railroad, which began construction of the line northward from New Castle in 1873. They built as far north to Mercer Junction that same year, and finished the route north to Stoneboro the following year. The line changed hands several times over the years, until the Pennsylvania Railroad acquired it in 1918. Some of the line was abandoned under PRR's ownership, while the rest of the line was abandoned under Penn Central.