Oldest firearm in the US found in Southern Arizona

 

Randy Chamberlain, July 2025

For one hundred years, a .50 caliber Wheellock musket, known as the Mayflower gun, was thought to be the oldest gun in the US.  It was given this nickname because Jon Alden, one of the first pilgrims to arrive in Plymouth, brought the musket with him to America when he arrived on the Mayflower in 1620.  

However, in the hot dry heat of Arizona, archeologists uncover a 480-year-old firearm, sitting on the ground in an old stone and adobe structure near the river in Santa Fe Valley.   The medieval-style wall or rampart gun, approximately 42 inches long and almost 40 lbs., is now believed to be the oldest firearm to be found in the continental US.  Through radiocarbon dating and other items found at the site, the archeologists have linked this cannon to a Spanish expedition lead by Francisco Vasquez de Coronado, between 1539 through 1542.

Coronado, a Spanish conquistador, led hundreds of men through Mexico, northward into the southwestern territories of the United States, in the search of the fabled Seven Cities of Gold.  In 1541, Coronado established a small outpost called San Geronimo III, near present day San Pedro River, as a base for more exploration in the area.  This began open warfare with the local tribes, likely the Sobaipuri O’odham tribe, who did not submit to foreign powers.  The battles were brutal.  Natives implored guerilla tactics, while the Spanish used cross bows, swords and black powder guns.  Weapons lay scattered around the area, which archaeologists used to interpret the events that had occurred hundreds of years later. 

The cannon, found in this area in 2020, was cast of bronze and copper, known for durability and anti-corrosive properties.  This makes the cannon perfect for all environments as the Spanish traveled and conquered more land.  It was not decorated, like many of the ornate European cannons of that time, which suggests that this cannon was cast closer to the source, either in Mexico or the Caribbean.   Local production of the cannon preferred practical weapons and not spending time on the look of the product.

In use, the rampart gun was mounted on a tripod or swivel, which made it more portable than the heavier cannons that were mounted on large, wood platforms.  The base helped absorb the recoil and maintain firing accuracy as well.  This type of weapon was often used for defense on the outer edges of camp with a range of over 700 yards.  Offensively, the cannon was used for attacks to breech forts, mud walls and less advanced adobe structures, making the following infantry assaults easier.  With its small buckshot caliber, holding up to 86 pellets a round, the cannon wouldn’t blow through heavier stone buildings, but its intimidating nature worked well to spread fear among the natives who didn’t have experience with firearm weapons. 

One surprise about this artifact is that it was never fired in battle.  There is no trace of black power in the barrel.  Evidence suggests there may have been a sudden attack on the camp and the Spanish didn’t have time to load the weapon and retreat with the valuable gun, opting to take items for personal survival instead.  Others suggest perhaps the operators of the cannon were among the first killed during the attack.  A second cannon was also found in the area, but the barrel had been blown apart.

Coronado never found the Seven Cities of Gold.  In 1542, Coronado and his men journeyed back to Mexico defeated and empty handed.  He had originally mortgaged his and his wife’s possessions and borrowed money for the voyage, so upon his return home, he was faced with many accusations and legal challenges, as he had lost everything and still owed money for his failed expedition.

The expedition left a violent mark on the Southwest region.  Many pueblos had been looted and the Tiquex War, one of the earliest battles between Europeans and the Indigenous people, left many people dead.  The Spanish lost the war and retreated, delaying the invasion by another 150 years.

Sources:

·         Oldest Firearm Ever Found in America Just Discovered!  by Discovery Future: May2025

·         Archaeology News Online Magazine, By Dario Radley: November 2024

·         Popular Science, By Andrew Paul: November 2024

·         USmessageboard.com

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About the Author:

Randy has been a decades long member of the NRA and the Civilian Marksmanship Program, he began collecting firearms in the 1970s and has owned more than 500 weapons. He will be contributing his vast knowledge of surplus and collector weapons.