If you purchased them from AA.com, the confirmation email you received after ticketing should indicate the fare class on the flight. It is located on the right had side of each row listing the flight. If you haven't gotten an email, but you can see the flights online under your AA account, then at the bottom of the page, click "Print trip and receipt." there each flight will have its fare class listed under booking code. If you purchased from an OTA (priceline/expedia/etc.) then I don't know if and where those may be listed, but you can usually call customer service and ask for the fare classes that the flights were booked into.