A slice of history could be unearthed in Massachusetts today, where crews are working to find a centuries-old time capsule at the Old State House in Boston.

Historians believe the capsule contains artefacts dating back to 1795, when it was buried under the cornerstone at Massachusetts State House by Governors Samuel Adams, Paul Revere and William Scollay.

Workers at the State House discovered the capsule’s location by chance as they attempted to find the source of a water leak.

If crews are successful, this will be the oldest time capsule ever found in Massachusetts, according to NECN News.

The contents of the box date back to Hanoverian times, when Britain was a colonial power, George III was on the throne, and William Pitt the Younger was the Tory Prime Minister. Over the Channel, the French Revolutionary Wars were in their third year.

Meanwhile in the US, the Declaration of Independence had been signed less then two decades ago and George Washington was President.

Reporters from WBZ Radio posted images of the operation on Twitter today.

The capsule last saw light in 1855, when emergency repairs were made to the building. It was then put back into place when the cornerstone was reset, according to records found by officials.

The Divisions of Capital Asset Management (DCAMM) and the Secretary of State’s office are overseeing the removal of the cornerstone from the southeast corner of the Bulfinch Building at the General Hooker entrance.

Once the container is uncovered, it will be sent to the Museum of Fine Arts for restoration and preservation, according to DCAMM officials.