A firearm discovered in Arizona may be the oldest ever found in the lower 48. When the 1539-1542 led by Francisco Vazquez de Coronado crossed the Santa Cruz River in Arizona, it appears they left behind a light bronze cannon, also known as a wall gun. Not only is the piece potentially the oldest in continental U.S. history, it is also the first ever connected to the famous expedition exploring the modern-day American Southwest, including sections of Arizona, New Mexico, Texas, Oklahoma and Kansas.
Tasked at finding the mythical "Seven Cities of Cíbola," Coronado instead stumbled across breathtaking landmarks like the Grand Canyon, not to mention countless Indian settlements. His expedition consisted of somewhere around 2,800 people.
While its age has only recently been determined by radiocarbon dating and optically stimulated luminescence, the firearm was actually found back in 2020 in the settlement of San Geronimo III, on the floor of a stone and adobe structure of Spanish origin. For dimensions, the 42-inch-long gun weighs some 40-pounds—not exactly any modern hunter's idea of a lightweight trekking gun. Its relatively simplistic design—indeed, nearly obsolete by the time of the expedition—indicates it was likely cast in either Mexico or the Caribbean, and was meant to be mounted on a wooden tripod for use. While no chronograph data is available concerning muzzle velocity, it did have a range of over 700 yards with lead balls, and could even fire multiple smaller projectiles at once in a pinch.
