Visitors to Mount Vernon might be surprised to see the key to the Bastille, the notorious French prison, on display in the central hall. In 1790, Gilbert du Motier—better known as the Marquis de Lafayette—sent the key to George Washington on behalf of the people of France. To understand why Lafayette did this, it is necessary to understand the special relationship that developed between Washington and Lafayette during the American Revolution.The bond between the two men grew so strong that they were more like a father and son, rather than a commanding general and his top-ranking officer. For Lafayette, there was no better person to receive the symbol of the end of ancient tyranny than the man who fought so bravely to establish the United States.At first glance, Lafayette might seem an unlikely supporter of George Washington. Born in 1757, he came from one of France's oldest families. His ancestors served in the Crusades and alongside Joan of Arc. When Gilbert was two, his father died f...