Benjamin Rumsey (1734–1808), the namesake of Rumsey Island and the Rumsey Mansion (the only colonial building that survived the decline of Joppa), was a delegate for Maryland to the Second Continental Congress and the first Chief Judge of the Maryland Court of Appeals for over 25 years (1778–1806). In 1768 Rumsey married the widow of Colonel James Maxwell, who had been the primary landowner in Joppa, and who had the "Rumsey Mansion" built between 1720 and 1724.
Rumsey relocated from Cecil County to Joppa sometime around 1771, after having the Rumsey Mansion substantially renovated. Benjamin Rumsey eventually acquired all the land where Joppa once stood, and all of the surrounding areas, and this came to be known as "Joppa Farm", a Slave Plantation. Upon Benjamin Rumsey's death in 1808, Joppa Farm passed to his son John Beal Rumsey and/or his grandson Charles Henry Rumsey. Upon Charles Henry Rumsey's death, his children sold Joppa Farm to the Murray family. James Murray is the last known private owner of Joppa Farm, though there was at least one more owner prior to the Panitz Brothers Company acquisition of Joppa Farm in or about 1961.
Maryland Historical Society records indicate the property was owned by the ""Maryland-Virginia Joint Stock Land Bank" in 1936. Charles B. Anderson Jr. Harford County Commissioner from 1970 to 1974 and County Executive from 1974 to 1978, acquired the dilapidated Rumsey Mansion and about 20 acres of surrounding grounds in the 1960s, and had it completely restored.
However, since then it has been utilized solely as a private residence by Ms.Virginia Anderson and is not open to the public for tours.