Construction of the railway began in 1846 and was completed in 1848. The line ran from Louth to New Holland and was officially opened on 28 March 1848 as the first section of the GNR. The line was constructed by the East Lincolnshire Railway Co (ELR), which leased it to the GNR when they could not raise sufficient funds to operate it. The GNR had obtained running rights over the MS&L from Grimsby to New Holland Pier; in return it allowed the MS&L running rights to Louth. The line south of Louth was extended as far as Boston in October 1848. The GNR ran the line with some of its famous C12 locomotives on the local services. From 1912-1913 Stirling single no.1 (preserved at the NRM York) was based at Louth shed (40c).