@adweek: Charles F. Frost helped shape @American Express in the 1960s, and his legacy is hiding in plain sight. The name "CF Frost," printed on American Express Cards traces back to this copywriter and the brand-building era he helped define. In this History of Advertising video, ADWEEK's Robert Klara unpacks the story behind the name and why it still matters today. #americanexpress #finance #historyofadvertising #History