Burlington is a city in, and the county seat of, Des Moines County, Iowa, United States. The population was 23,982 in the 2020 census, a decli…Burlington is a city in, and the county seat of, Des Moines County, Iowa, United States. The population was 23,982 in the 2020 census, a decline from the 26,839 population in 2000. Burlington is the center of a micropolitan area, which includes West Burlington and Middletown, Iowa, and Gulfport, Illinois. Burlington is the home of Snake Alley, the crookedest street in the world.