Credit and debt appear to be natural, permanent facets of Americans' lives, but a debt-based economy and debt-financed lifestyles are actually recent inventions. In 1951 Diners Club issued a plastic card that enabled patrons to pay for their meals at select New York City restaurants at the end of each month. Soon other «charge cards» (as they were then known) offered the convenience for travelers throughout the United States to pay for hotels, food, and entertainment on credit. In the 1970s...