The Plaza dates to the early 1600s, when Santa Fe was settled by the Spanish. As in other colonial towns, it was where soldiers gathered and where the governor's palace stood.
When Mexico won independence from Spain in 1821, the Santa Fe Trail opened between Missouri and New Mexico. Its western end was this Plaza, where wagon caravans camped and unloaded goods.
After New Mexico became a US territory, a fence was built around the Plaza to keep out animals, and trees and paths were added. New Mexico became the 47th state in 1912. Today the Plaza is a National Historic Landmark.