Le Mars was platted in 1869, but no lots were sold until the Iowa Falls and Sioux City Railroad, later part of the Illinois Central Railroad, arrived in 1870. Railroad magnate John I. Blair hosted an excursion to the new town, which was then called St. Paul Junction. Blair asked the women in the party to name the town, and they submitted an acronym based upon their first names' initials: Lucy Ford and Laura Walker, Ellen Cleghorn or Elizabeth Underhill, Martha Weare and Mary Weare, Adeline Swain, Rebecca Smith and Sarah Reynolds. (Note that some letters represent more than one person.) There was some subsequent uncertainty about who the women of the acronym actually were. For example, the city's web page contains a somewhat different list.