A Florida man found a rusty object in his back yard. Then the bomb squad came.

A Civil War era mortar found in a man’s St. Augustine backyard.
A Civil War era mortar found in a man’s St. Augustine backyard. St. Johns County Sheriff’s Office

It’s not every day you find a relic in your own backyard.

Last year, St. Augustine resident James Cooper was digging a grave for his dog when he happened upon something very, very old. We’re talking Civil War era.

At the time, the man assumed the curious object, weighing between 15 and 20 pounds and measuring 8 inches in diameter, was an old cannonball.

But on Tuesday, while police were at his home about an unrelated matter, Cooper decided to show it to them. It turns out that the artifact was something else: a siege mortar from the war that ran from 1861 to 1865. And there’s a possibility the weapon is still active.

“We have to run tests to see if there might be gunpowder in it or if it’s inert after all these years,” St. Johns County Sheriff’s Office Cmdr. Chuck Mulligan told The St. Augustine Record.

A bomb squad was called to the home on State Road A1A, and the device, used to propel explosive shells, was carefully transported for evaluation.

According to the police report, an officer at the scene observed “a spherical metal object with heavy corrosion over the majority of the surface … it was deemed a possible threat to public safety and was seized.”

Andrew Thomson, an archaeological conservator at the St. Augustine Lighthouse and Maritime Museum, said the find was rare because “there wasn’t a lot of Civil War action in this area.”

Local historian Susan R. Parker is aware of some Union vessels anchored offshore during wartime.

That leaves the possibility that the mortar may have belonged to a collector of curios who later disposed of it, she added.