Hi: My 6th great-grandfather was Evan Watkins who operated a ferry from the mouyh of Canagochego Creek in Maryland across the Potomac to Evan Watkins Landing. This was in 1744 in what was then Frederick Co., VA. There is supposed to be a monument and a white painted brick house at Mainstone on the Potomac. I would like to know if that monument and that house are still standing? Thank you, Annie