In 1784, the French mathematician Charles-Joseph Mathon de la Cour wrote a parody of Benjamin Franklin’s then-famous Poor Richard’s Almanack. In it, Mathon de la Cour joked that Franklin would be in favour of investing money to grow for hundreds of years and then be spent on utopian projects. Franklin, amused, thanked Mathon de la Cour for the suggestion, and left £1,000 each to the cities of Philadelphia and Boston in his will. This money was to be invested and only to be spent a full 200 years after his death. As time went by, the money grew, and in 1990 Boston received an impressive $5 million and Philadelphia $2.3 million, which was spent on charitable causes on behalf of Ben Franklin.[1]
Actually they did:
Source