Beginning in the 16th century, Spain established missions throughout New Spain, in an area known today as Mexico and the Southwest United States. This was part of their effort to colonize the region. These religious outposts didn’t necessarily have a church, but were settlements to establish Spanish presence and convert the Native Americans.
The church at Mission San Xavier del Bac is the oldest intact European structure in Arizona. The Baroque church is called the White Dove of the Desert.