Plains is a city in Meade County, Kansas, United States. As of the 2020 census, the population of the city was 1,037. It is located along U.S. …Plains is a city in Meade County, Kansas, United States. As of the 2020 census, the population of the city was 1,037. It is located along U.S. Route 54 highway. It is notable for the width of its main street which is the widest in the United States at 155 feet 5 inches across.