Hundreds of miles from its supply center in Chihuahua and just freed from the grip of Spain's mercantilist colonial policies, New Mexico was ripe for foreign commerce when the first of the Missouri traders arrived in Santa Fe in 1821. For the next forty years trade flourished between Americans hawking anything that would sell, often at incredible profit, and New Mexican buyers hungry for all types of manufactured goods. But the frontier moved inevitably westward, goods became more readily available and consequently less expensive, and the railroad at last replaced the mulewhackers who had long plied the Santa Fe Trail.