Jim Johnston is a lawyer, writer, and lecturer in Bethesda. He has published four books and writes regularly for newspapers and magazines. His topic is “The Potomac, A History of the River, Land and People.”  The Potomac River, the dominant geological feature of Montgomery County, has also played a dominant role in American history. It was the first interstate waterway in North America, the spawning ground for the Constitution, and a protective barrier in the Civil War. To travelers today, it is a time tunnel to 250 million years of history. Learn this history from Jim Johnston and then walk along the river yourself to see the Potomac in a new way.