The M&N began extending their main line north from Hilbert Junction, Wis., in 1872. Most of the 27 miles of grading and bridging had been completed by the end of the year. They started laying rail in the spring of 1873 and they reached Green Bay, Wis., on 6 June 1873. The first passenger train arrived on 19 June. Scheduled train service began on 25 June.
In 1874, the M&N constructed a bridge across the Fox River in order to extend their tracks from Green Bay into Fort Howard, Wis.
The majority of this stretch of the main line, save 2 miles of track from the Hilbert depot to Ott Rd., is now the Fox River State Trail.