The Northwestern (Winona and St. Peter) Railroad crossed the Yellow Medicine River's North Branch where engines stopped to fill with water and deliver the rural mail. Settlers, mostly of Norwegian and other Scandinavian descents had settled and homesteaded the area.

In 1873 a Norwegian Lutheran Church was established one mile south of what would later become its permanent home on the south edge of the yet to be formed city. The railroad stop, with its single stately cottonwood tree among the wide open prairie, became known as Lone Tree Station. Later the unincorporated community of Harstad was established, just across the Lincoln County line south of what would later be platted as a city. Harstad was named for the new Postmaster, G.A. Harstad who became Postmaster at the United State Post Office, which received service from the Lone Tree Station just a few tenths of a mile north.

In 1881, the railroad established a permeant station, platted a city, the United States Post Office was relocated to the Train Depot, and a milling company was established in by L.C. Porter, for whom Porter was named. Later in 1881 the Van Dusen Elevator Company erected a warehouse in Porter as well, and Ole Dahl became the city's first resident as a grain buyer for both the Porter Milling Company and Van Dusen Elevator. By then end of 1881, W. E. Drummond erected a 12 x 12 foot Blacksmith Shop which he operated.