CNN  — 

After going missing for more than 50 years, a firearm dating back to the Revolutionary War has been recovered and donated to a Philadelphia museum, the FBI says.

The .78-caliber musket, which was stolen from Valley Forge, Pennsylvania, in October 1968, was donated to the Museum of the American Revolution in Philadelphia on Monday, after investigators recovered the weapon earlier this year, according to a news release from the FBI’s Philadelphia office.

“This historic weapon from the American Revolution was taken and hidden from generations of Americans. Now, this priceless piece of American history will finally be back in its rightful place on view at the Museum of the American Revolution,” Montgomery County District Attorney Kevin R. Steele said in the release.

The artifact was among several Revolutionary War-era items taken during a string of thefts that occurred in the 1960s and 1970s in the area of Valley Forge Park.

The investigation into the missing items began in 2009, and in April, the FBI announced several stolen guns had been recovered and given to the Museum of the American Revolution.

“The recovered firearms were among a wider swath of items looted during these robberies, for which little evidence as to the perpetrators had been uncovered in the past,” the April news release stated.

However, 10 of the items looted from Valley Forge Park and other locations, including the recently returned musket, remained lost. In April, the FBI’s Philadelphia office and its partners sought help from the public in recovering those missing items.

“A short time later, the investigative team received a tip from a member of the public identifying the whereabouts of the musket,” according to the FBI.

A detective from the Upper Merion Township Police Department in Pennsylvania shared the FBI’s story with a historical firearms expert and professional appraiser who had worked on a past case with the department, according to a release.

The appraiser, Joel Bohy, recognized the musket from an event where he’d spotted it, realized how rare the firearm was and taken a photo of it.

“There’s only two others known,” Bohy told FBI officials.

Investigators were able to use that tip to trace the musket to a Maryland-based antique firearms collector, who investigators say had no connection to the 1968 heist nor any knowledge that the musket was stolen.

The collector voluntarily handed over the musket to the FBI’s Art Crime Team, a release stated.

“Chubb, the insurer whose predecessor company paid the insurance claim in 1969, became the owner of the musket. The company donated it to the Museum of the American Revolution, signing over the deed at the July 1 ceremony,” according to a release.

FBI investigators said they continue to search for other relics taken in 1968 from Valley Forge.