The source is an extensive Wikipedia article detailing the history, products, and operations of American Express (Amex), a multinational financial services corporation. It begins by outlining the company's origins in 1850 as a freight forwarding business and tracks its evolution into a major player in payment cards, including charge, credit, and traveler's cheques. The text chronicles significant milestones such as the introduction of its iconic cards and major corporate acquisitions and divestitures, like its venture into the brokerage business with Shearson. Furthermore, the article covers Amex's marketing strategies, global presence through various offices, and important legal and financial events, including its 2008 conversion to a bank holding company.