Oldest Known Firearm in U.S. Unearthed in Arizona

A 500-year-old bronze cannon linked to Coronado's expedition reveals insights into early Spanish-Native American conflicts.

Archaeologists have discovered a 40-pound, 42-inch-long bronze cannon in Arizona, identified as the oldest firearm ever found in the continental U.S.
The cannon, known as a wall gun, dates back to the 1539–1542 expedition led by Spanish conquistador Francisco Vázquez de Coronado.
Radiocarbon and luminescence dating confirmed its origin, and its plain design suggests it was likely cast in Mexico or the Caribbean rather than Spain.
Historical accounts tie the cannon to San Geronimo III, a short-lived Spanish settlement abandoned after an attack by the Sobaipuri O’odham people.
The discovery highlights the technological and cultural dynamics of early Spanish exploration and the significant resistance from Indigenous communities.