Blisworth Tunnel was the only section unfinished. This was despite the tunnel having been under construction for seven years: the gap was filled by a temporary horse-drawn tramway over the top of the hill, with goods being transported from boat to wagon and back again. The tramway, built in 1801, was Northamptonshire's first railway. In March 1805, the tunnel was finally opened and the rails were used to connect the main line of the canal to the River Nene until the branch canal to Northampton was constructed. Until the 1870s travel through the tunnel was only achieved by men lying on their
Union Canal (Pennsylvania) closure in 1881. In April 1950, the Union Canal Tunnel was purchased by the Lebanon County Historical Society. The tunnel was placed on the National Register of Historic Places on October 1, 1974. It was designated a National Historic Civil Engineering Landmark in 1970. On April 19, 1994, the tunnel was designated a National Historic Landmark by the Secretary of the Interior Bruce Babbitt. The tunnel is open to visitors in the Union Canal Tunnel Park. A restored portion of the canal along Tulpehocken Creek is maintained by the Berks County Parks System at the Union Canal Towpath Park in