The Baron of Arizona: The Great 12-Million-Acre Land Swindle, by E. H. Cookridge (HC, 1967, weak spine, $1.50)
James Reavis' job was to handle land claims. Some of the ownership documents looked pretty questionable, which gave him the idea to forge his own. Eventually he got really good at this "other" job.
"He produced a claim to a gigantic property in Arizona and New Mexico, worth half a billion dollars in today's money, which had ostensibly been granted by the crown of Spain in the 18th century to one ' Don Miguel Nemecio Silva de Peralta y de la Cordoba.' To bolster his claim, he 'discovered' a direct descendant of the Peralta family and married her, calling himself thereafter Baron de Peralta y Cardoba; actually she was a part-Indian from California, upon whom he performed a Pygmalion act so successfully that he passed her off as genuine in the royal courts of Spain and England."
His land ownership claims were supported by senators and tycoons, and even the Southern Pacific Railroad itself. Over the years he made a fortune on rents he collected. When the Surveyor General of Arizona reported him as a fraud, Reavis immediately sued the US government for $11,000,000!
Truth sometimes is stranger than fact. Look for this in the box of fraud books, on the floor in front of the general non-fiction.