It was the combined project of a group of people purportedly dissatisfied with city life in Chicago, who in 1895 formed what they called "The Plymouth Society of Chicago" and William E. Smythe, who was the chairman of the executive committee of the National Irrigation Congress and a famous irrigation promoter.

Mr. Smythe was determined to found a colony to serve as a striking argument in favor of his project - irrigation.

He spoke throughout the east, urging young and old men to go west in colonies and develop the country with the help of irrigation.

The Plymouth Society of Chicago selected a committee to investigate the irrigated Payette River Valley in the five-year-old state of Idaho, and another site in Colorado, to be purchased for the colony.

The present city of New Plymouth was on the drawing boards in Chicago, designed as a town able to be self-reliant through the use of irrigation, solidly built on an agricultural and railroad economy.

The town was platted with a horseshoe shape with its open end facing to the north, toward the railroad and the river.

This area was planned as an industrial zone, and the acre tracts around the horseshoe were the residential lots.

The homes were to be built on the street side and the balance of the acre for garden and pasture for the family cow and the driving team.

Plymouth Avenue, the main street and principal business thoroughfare, was surveyed (16 feet off the section line) down the center of the horseshoe from the railroad on the north through the Boulevard on the south.

According to the United States Census Bureau, the city has a total area of 0.69 square miles (1.79 km2), all of it land.

Also, a system of ditches parallel the roads and drain into the canal, giving each landowner who pays for a share access to irrigation water.