Charles Ponzi (1920): Boston Post series (1920) — Section 1022: Boston Post series (1920)

The Boston Post, with help from financial publisher Clarence W. Barron, published investigations in July and August 1920 that compared the coupon market's real size with Ponzi's intake. State and federal authorities moved as redemptions and a run developed. Ponzi surrendered in August 1920. He pleaded guilty to federal mail fraud and later faced Massachusetts larceny convictions after a first state trial hung and a second convicted him.

The dollar scale was of its time: contemporary estimates put liabilities on the order of $15-20 million in 1920 dollars, a fraction of later cases in this atlas, but the legal and linguistic imprint was larger. English-language law and journalism adopted 'Ponzi scheme' as the name for a fraud that pays earlier participants with money from later ones. Earlier operators had used the pattern; this collapse named it.

The Boston Post series, federal mail-fraud papers, and Massachusetts larceny dockets are the primary sources. They describe a 1920 promotional collapse, not a puzzle about whether the coupon story could have scaled. International Reply Coupons existed. Postal authorities sold them so a correspondent abroad could send a reply without buying local stamps. Small price differences between countries were a known curiosity among people who followed postal circulars.