How to Get a List of Your Previous American Express Credit Cards

With Amex only granting one lifetime bonus for every type of credit card, it’s important to know what types you have had.

http://www.milevalue.com/how-to-get-a-list-of-your-previous-american-express-cards/

According to this blog post, you can ask via online chat and the rep will (slowly) type out the list for you.