By 1778 the colonists of Baltimore gathered to sign a declaration of allegiance to the United States of America. Jonathan Plowman signed proudly as did his sons on hand. Some were away serving the cause and names were simply written in; now the DAR (Daughters of the Revolution) won't accept this as proof of service. This same year many factories were established in and around the Baltimore area to provide the goods that the merchants like Plowman could no longer get from abroad and had been prohibited from making in the Americas by the British. Life for merchants such as Jonathan Plowman was hard, with a requirement to register their ships in Annapolis before leaving or arriving in Baltimore. In 1780 they finally rectified this hardship with a Customs Office in Baltimore.