From The Comanche Empire, by Pekka Hämäläinen (Yale U. Press, 2008), pp. 150:
In 1821, Spain’s American empire collapsed, and the resulting confusion in the Southwest opened the floodgates for Comanche–U.S. commerce. Only a year later, Stephen F. Austin reported that eastern Comanche rancherías had become the nexus point of three well-established trade routes that connected them to U.S. markets along the Mississippi valley. The northernmost route linked eastern Comanchería to St. Louis via a chain of Native middlemen traders. Below was the Red River channel, which funneled traders from Vicksburg, Natchez, Baton Rouge, and New Orleans into the heart of eastern Comanchería. The busiest of the trade routes was the southernmost one, leading from eastern Comanchería to Nacogdoches, which had nearly expired during the 1812–13 revolt in Texas and then, like Natchitoches, became a haven for American merchants and filibusters. With close ties to Natchitoches and New Orleans, Nacogdoches grew into a major trading community, boasting an annual trade of ninety thousand dollars in the early 1820s.