Which two airlines are among the largest in the U.S. that account for a significant portion of seat capacity?

American Airlines and Delta Airlines are recognized as two of the largest airlines in the United States, significantly contributing to the country's overall seat capacity. These airlines have large fleets and operate numerous domestic and international flights, making them key players in the airline industry. Their extensive networks and established market presence allow them to hold a substantial share of available seats in the market, catering to a wide range of passengers, from business travelers to leisure customers. Their capabilities in terms of both infrastructure and operational range underscore their leadership in the industry, distinguishing them from other airlines that may have different service models or operational focuses.