Mass. Moments alerts us that on July 24, 1920, the Boston Post published an article detailing a scheme run by an Italian immigrant named Charles Ponzi that was in the middle of defrauding large numbers of people of millions of dollars from an office on School Street.
Ponzi fixed his attention on International Reply Coupons that could be used to buy postage stamps in foreign currencies. Exchange rates had not kept pace with global currency changes after World War I. Ponzi concluded that he could buy the coupons in bulk from countries with depressed currencies, like Italy and Romania, use them to purchase U.S. stamps at a discount, and redeem the stamps for American dollars. It was simple, and it appeared to be legal. Ponzi was not sure just how redeeming stamps for cash would work, but in December 1919, he opened for business anyway.
The BPL has a number of Ponzi photos by Leslie Jones, from the days after the scheme was exposed in 1920 to his deportation trial in 1934 (in the photo below, he's standing with his wife Rose, who divorced him and later became the secretary at the company that owned the Cocoanut Grove nightclub).