[dropcap]D[/dropcap]r. John R. Brinkley, the most notorious quack in America, filed for bankruptcy in a Texas court on Jan. 17, 1941 in a last-ditch attempt to fend off creditors and lawsuits.

Traditionally susceptible to health-care charlatans, Americans between the World Wars seemed especially vulnerable to con men in white coats. But no one came close to Dr. Brinkley, who in less than 20 years fleeced the faithful for $20 million.

A lowly railroad relief agent in his youth, the future master of...