Patty Cannon, whose real name might have been Lucretia Patricia Hanly, was born around 1759, 1760, or possibly 1769, in either Maryland or Delaware. She married Jesse Cannon, a local farmer, and settled near the border between Maryland and Delaware on the Delmarva Peninsula. After her husband's death, Patty Cannon began running a tavern, which served as a central location for her criminal activities.

Around 1810, Patty Cannon formed the Cannon–Johnson Gang alongside her son-in-law Joe Johnson and other accomplices. The group became notorious for their ruthless practice known as the Reverse Underground Railroad—abducting hundreds of free African Americans and runaway slaves, transporting them from the Delmarva Peninsula into southern states, and selling them into slavery.

The gang operated by luring or kidnapping individuals, using violence, deception, and brutality. Patty herself was reputed for her cruelty, with several witnesses testifying to her direct involvement in murders and torture. Victims who resisted were often killed and secretly buried on her property or nearby locations.

In April 1829, after numerous complaints and increasing suspicion from local authorities, Cannon was finally arrested. A search of her property uncovered multiple human remains, providing tangible evidence of her horrific crimes. Patty Cannon confessed to at least four murders during her imprisonment.

However, before she could be formally tried for her crimes, Patty Cannon died by suicide in her cell on May 11, 1829, reportedly by ingesting poison.