Welcome. This site documents the history of the Guilford area of Howard County, Maryland—an unincorporated community that started along the Little Patuxent River. We take an evidence-first approach to both industrial archaeology (mills, quarries, railroads) and the social history of the people who lived and worked here. The “Between the Bridges” corridor—anchored by the National Register–listed Guilford Quarry Pratt Through Truss Bridge and the Bollman Truss Bridge— as well as the Washington Branch of the B&O, North Laurel and Jessup, is the central focus .