"Sha Ach Wah", which means spruce tree or green bush in Chippewa, the local Indian language, was the inspiration for the name of the city of Greenbush. Settlers started coming into this area in the late 1880s, but the big influx of settlers began 1900. They moved here because of inexpensive land: the Homestead Act gave them 160 acres free if they would put up living quarters and develop a few acres into fields. The early settlers were almost all Polish, Bohemian or Scandinavian, and it still remains that way today.

The original setting of the city was on a ridge of what used to be the shores of ancient Lake Agassiz. This village is now referred to as "Old Greenbush". The beginning of Old Greenbush occurred in 1898 when Olaf Hildahl built a general store approximately two miles northeast of the present city. Shortly thereafter, T.T Lanegraff and son moved their agricultural tools and equipment business from their farm to the ridge. By 1904, the Lear Brothers' farm implements and blacksmithing, Chilstrom's Hotel and Livery, Farmer's and Merchant's State Bank, Mike Johnson's Grocery, and Sander's Greenbush Journal had followed. Thorpe's sawmill was located near the little town. And we mustn't forget Mr. Nixon's business, a "blind pig", to use a colorful expression of the time. Mr. Nixon was a bootlegger. Old Greenbush was developing rapidly.

In 1904, the great railroad came to the area. It expanded north from Thief River Falls to where present day Greenbush is, where it stopped construction. Being the progressive village that it was, Greenbush merchants moved their businesses, buildings and all, to the new town known as "West Greenbush". All that remains of the old town today is Hvidso Cemetery along Highway 11, more commonly referred to by the locals as Pioneer Haven.

New Greenbush grew quickly and incorporated in 1905. Before long, there were three hardware stores, a print shop, three banks, livery stables, two blacksmith shops, a general store, four small restaurants, four beer parlors, a lumber yard, a large creamery, four implement dealers, three new car dealerships, thirteen businesses with gas pumps, a shoemaker, three wool buyers, three cream stations, four grass seed buyers, five or six grocery stores, two barber shops, two fur and hide buyers, and a hotel. All of these businesses with a population of 450 people.

Just three or four years later the rail line to Warroad was completed and it ran right through the site of Old Greenbush.