The largest airlines in the United States are the three main full-service legacy carriers – American, Delta and United – who each generated over 40 billion U.S. dollars of revenue in 2018. These airlines are termed legacy carriers as they had established interstate routes prior to deregulation of the U.S. airline industry in 1978. In the decades since deregulation, these three airlines have merged with or acquired the majority of carriers existing prior to deregulation, leading to a more concentrated full-service market. Deregulation also led to the emergence of new low-cost carriers though, such as Southwest, who now have a larger share of domestic market than any single legacy carrier. However, in terms of revenue, the freight company FedEx is a larger airline than Southwest, owing to their air cargo operations.
Air travel is a very safe mode of transportation, with there being no fatal accidents involving commercial U.S. air carriers since 2013. Similarly, there are very few reports of serious injuries resulting from air accidents – less than ten per year for every year of this decade. Air travel is less safe when taking into account general aviation, which includes private air travel (e.g. for business), flying for sport or as a hobby, and other assorted activities such as firefighting, photography and search and rescue operations. In 2017 alone, there were over 1,200 accidents in U.S. general aviation, resulting in 330 fatalities.