Which western trail was created in 1820 to facilitate trade with Mexico?

The Santa Fe Trail connected Missouri with Santa Fe, then part of Mexico, and was used to expand trade between the United States and Mexico. It was opened for regular trade around 1821, so it is the western trail the question is referring to. The California and Mormon Trails were associated mainly with migration west, while the Butterfield Overland Trail was a later stagecoach route.

AI-written and checked against the verified answer.