One reason as to why William Becknell's route to Mexico became famous is that unlike the immigrant trails of California and Oregon, the route was a commercial trail with a lot of economic benefits that could be gained by trading with Mexican people.
Trade on the trail developed rapidly after William Becknell's three wagons reached Santa Fe in mid-1822. There was considerable demand of basic as well as luxury goods in Sana Fe, the end destination of the trail and this prompted traders to travel there to sell their goods.