In 1791, before Washington DC became the capital of the United States, surveyors placed a series of 40 boundary stones to mark the original 100-square-mile District of Columbia. Today, many of those historic markers still survive -- hidden in neighborhoods, parks, and along roads around the capital. Join me as I drive around Virginia, Maryland, and Washington DC searching for these forgotten pieces of American history and visit several of the original boundary markers placed between 1791 and 1792. These stones witnessed the birth of the nation's capital and are some of the oldest surviving monuments connected to the creation...