Joppa is a former town and current planning region of Harford County, Maryland. Joppa was founded as a British colonial settlement in the early 18th century and early county seat and courthouse of old Baltimore County erected / laid out in 1659 in northeast Maryland. It takes its name from the Biblical town of Joppa in the ancient Holy Land.The town of Joppa on the Gunpowder River just off the Western Shore of the Chesapeake Bay was a designated "Port of Entry" by the colonial legislature, the General Assembly for the Province of Maryland and traded internationally in agricultural products, especially tobacco. At its peak, the port was home to about 50 homes, a church, prison, inns, shops, schools, armament factories, and warehouses. However, with the rise of the third Baltimore on the Basin of the Northwest Branch of the larger Patapsco River after 1729 and the provincial capital on the Severn River of Annapolis, Joppa declined as a port, and was slowly abandoned.