Baggage Allowances

From AA's website:

Type of baggage Number Allowed Size Allowed
(length + width + height) Maximum free weight allowed

Carry-on 1 45 in/114 cm 40 lbs/18 kgs.
Checked 2 62 in/157 cm each 50 lbs/23 kgs
$25 USD charge each for
bags weighing 51-70 lbs.

There is more information regarding additional overweight baggage (let's hope that is not necessary).