Located in Meade County and originally founded in the late 1800s as West Plains, the town was officially platted in 1885. In 1901-1902, Albert Hempel and Don T. Edwards laid out what would become Plains' most iconic feature, its unusually wide main street. When asked why they made it so wide, they simply said, "There was plenty of no good ground, so it just as well be a street."

The street remained unpaved until 1929, when the city council chose to brick half of each side. Mayor Simon Elliott later added a raised brick sidewalk down the center, creating Simon's Monument, a three-block walkway that doubled parking and became a unique landmark. Today, from storefront to storefront, the street spans 155 feet, 5 inches, giving Plains the distinction of having the widest main street in the United States.