American Airlines seat selection is offered during the booking or check-in process. You can choose Preferred, which includes main cabin extra legroom, preferred, or regular seats. Seat selection or change is allowed through the American Airlines Manage Booking feature, where you can modify your seat at any time up to departure. Want a window, an aisle, or more legroom? American Airlines seat selection has got you covered with an experience suiting your preference and need for travel.
https://www.americanflyhigh.com/blog/american-airlines-seat-selection-policy/
