A groundbreaking discovery in southern Arizona has unveiled the oldest known firearm in the continental United States. A bronze wall gun, dating to the Coronado expedition of 1539–1542, was excavated in the Santa Cruz Valley, at a site discovered several years ago. This rare find sheds light on the weaponry and interactions between Spanish explorers and Native American communities during the early years of European colonization in the American Southwest. The firearm, identified as a medieval-style cannon, measures 42 inches (106.7 cm) in length, weighs approximately 40 pounds (18 kg), and has a bore diameter of .95 inches (24.7 mm), equivalent to a 5-gauge shotgun. Likely used to breach fortifications, this piece is emblematic of the expedition's militarized approach to exploration, and is described in a study published in the International Journal of Historical Archaeology. 16th Century Spanish Coronado Expedition Site Found in Arizona The Search for Cibola, the Seven Cities of Gold Read moreSection: ArtifactsAncient TechnologyNewsHistory & ArchaeologyRead Later