By 1718, the Spanish had build San Antonio de Valero (and 5 other missions) . What was the significance of this event?

Known today as The Alamo, this Spanish mission complex was the first of the San Antonio missions founded to convert the local American Indians to Christianity. The mission eventually became a community of Spanish, Mexican, and American Indian Catholics.

Explanation:

the completion of the erie canal spurred the first great westward movement of american settlers, gave access to the rich land and resources west of the appalachians and made new york the preeminent commercial city in the united states.