my great grandfather:Edward B. Duvall of Md.oldest ham radio ham operator. worked for President Roosevelt among others. also an avid photographer. Died 1974 buried at Ft. Lincoln. Ancestors date back to 1600's from France-graves of these persons are at Trinity Church located on Rt. 450 near Bowie, Md.Does anyone out there have more history on the family, if so please e-mail, thank you!