Actually, I've been doing a lot of mileage runs in the U.S. and American airlines are not strict at all/have different rules. Only bulkhead seats (i.e. with no seat in front) are required to put everything overhead. This is different from European regulations, where any row that is an emergency row must be completely clear for takeoff and landing.

Since the OP might be American, I wanted to make that clear.

It's also worth pointing out that most European low cost carriers incentivise / train their staff to find ways to charge people for excess baggage. Very rarely do you get the friendly "we're happy to check your luggage at the gate for free"