Hamilton, who was then captain of a New York artillery company, sent the letter at the end of the Revolutionary War. Lafayette, a French aristocrat, was helping the Americans in their fight against the British. In the letter, Hamilton warned Lafayette of “hostile” forces coming to Rhode Island and endangering the French troops. An archive employee who stole the letter was arrested in 1950 and found to have sold it, along with other documents from America’s founding fathers, to rare book dealers, Massachusetts courts have heard. In November 2018, the letter appeared at an auction house in Alexandria, Virginia, before being taken into FBI custody the following year. The Commonwealth Museum’s July 4 exhibit is the first opportunity the public will have to see the letter since it was returned to Massachusetts, the news release said. The exhibit also includes other original documents from the 18th century, such as a letter from John Hancock to the Massachusetts Assembly declaring independence from Great Britain and a letter from George Washington to the Massachusetts General Court with a copy of the Declaration of Independence.