Claim: The Hangsaman was referenced from Paula Jean Welden's case, while it's the novel's name was based on an old fold ballad.
Evidence: The official publisher's description of Hangsaman says the novel is "loosely based on the real-life disappearance of a Bennington College sophomore in 1946," referencing the case of Paula Jean Welden. The novel takes its title from an old folk ballad.