[1] It housed a garrison of about fifty cavalry and or infantry soldiers and was intended to protect Spanish settlements and missions in the valley of the Santa Cruz River.

In 1774, Tubac's commander, Captain Juan Bautista de Anza, assembled the expedition that explored a land route from the Santa Cruz Valley to California.

The force under Lieutenant Juan Fernandez Carmona was enlarged to fifty-six officers and men and received orders to proceed 40 miles (60 km) north to a site within present-day downtown Tucson, Arizona.

Leaving the colonists at Monterey, de Anza continued north as far as present-day San Francisco, where he selected sites for the mission and presidio.

By the early years of the 19th century, Tubac's garrison continued to protect the area from raids by Apache Indians.

The presidio of Tubac was resettled in the 1880s and by the 1886 surrender of Geronimo, the Apache were no longer a threat to settlers in that part of Arizona.