All major American airlines have the same carry-on luggage policy. You are allowed to have one 22-by-14-by-9-inch carry-on bag that weighs up to 40 pounds.
Most airlines also will allow you to carry on a personal item such as a purse or laptop with a maximum size of 6-by-13-by-17 inches. The size of the personal item, however, may vary among airlines, so check with your ticketed airline before your flight.
Almost all major American airlines allow you to have two free checked bags on international flights, each with a maximum size of 62 linear inches (length + width + height) and a maximum weight of 50 pounds. If you pay an excess baggage charge, the maximum weight is 70 pounds. Delta Airlines charges $50 for a second checked bag on all international flights.
Fees will apply to all excess baggage--either oversized or overweight. Excess luggage charges are applied to your first flight and again anytime you change carriers and re-check your luggage. The amount of the fee depends on the airline and your destination.
All liquids in carry-on luggage must be packed in individual containers no larger than 3 ounces and placed in one transparent quart-size resealable bag that must close easily. One bag of liquids per passenger is allowed. Other liquids need to be packed in your checked luggage.