Actually, I got my letter today from them, here is what it says:
Reason(S) for Our Decision:
Federal regulations prohibit us from approving applications that are taken over the phone from applicants who are under the age of 21. Because of this we cannot accept applications over the phone from under the age of 21.
Please apply again online at http://www.americanexpress.com/apply
. If our information about your age is incorrect, please call us ***-***-**** so we can update your information and process your application. Thank you for your interest in American Express Cardmembership.
An important notice concerning your rights is included. The creditor is American Express Centurion Bank.
So basically they would not approve me because I am 19? I didn't know you had to be 21 to become an Amex member. And also I applied online and not over the phone, so I didn't really apply over the phone.