Cavalier County's place names include railroad townsites, rural settlements, ports of entry, post offices, and vanished villages founded from the early 1880s into the 1970s. Many communities were established by the Great Northern Railroad or the Soo Line Railroad, while others began as small ethnic or religious settlements, trading or manufacturing sites, or local service centers. Some places grew to modest peak populations before declining or disappearing when rail lines bypassed them, industries failed, or larger towns outcompeted them. Langdon became and remains the county seat after a fiercely contested 1889 election clouded by fraud allegations, while other communities such as Lemon and Olga also sought that role and lost. Several names reflected settlers' origins in places such as Denmark, Ontario, Scotland, Norway, Russia, and Wales, and some sites later changed names, merged, were absorbed by neighboring towns, or never fully developed at all. The county also included unusual places such as Hove Mobile Park, created during the 1970s A.B.M. housing boom, Nekoma near the Safeguard A.B.M. and Missile Site Radar, and Marie, a mapmakers' copyright town believed never to have existed.