Patty Cannon is believed to have come to Maryland from Canada in 1802. She moved into a house that was on the corner of Dorchester County and Caroline County in Maryland. Across the way was the state of Delaware which was very convenient for Patty Cannon’s trade.

Patty Cannon and her daughter’s husband Joe Johnson ran a slave sale trade. They would steal slaves or free blacks and sell them back down south to the plantation owners. When they brought them back to the house they would hide them in the basement, hidden rooms in the house and in the attic. They would take the slaves in covered wagons to Johnson’s Ferry (now Woodland’s Ferry). At the ferry they would sometimes meet a schooner which would take them down the Nanticoke River to the Chesapeake Bay and onto Georgia slave markets. This went on for many years with no one willing to turn them in to the police.

When they were caught in May, 1822 it took some coordination. It seems that when Patty Cannon knew the police were coming she would slip across state lines and away from that police force. Upon capture Joe Johnson was sentenced to 39 lashes which was carried out. Patty Cannon was charged with four murders.  While she was in her cell in Georgetown, Delaware she killed herself.