Mo. Rev. Stat. § 150.470: Peddler defined.

Whoever shall deal in the selling of patents, patent rights, patent or other medicines, lightning rods, goods, wares or merchandise, except pianos, organs, sewing machines, books, charts, maps and stationery, agricultural and horticultural products, including milk, butter, eggs and cheese, by going about from place to place to sell the same, is declared to be a "peddler" .