There are many options for flying internationally to and from the United States, but the three largest airline alliances that reach around the globe are Star Alliance, SkyTeam and OneWorld, as of 2015. The airlines of Star Alliance, the largest of the three, serve more than 1,000 airports in 194 countries.
United Airlines is a founding member of Star Alliance and is the main American airline in the group, according to Star Alliance. United Airlines has hubs in Chicago, Denver, Guam, Houston, Los Angeles, New York, San Francisco, Tokyo and Washington, D.C., and it services more than 370 destinations worldwide.
Delta Airlines, the main American airline for SkyTeam, is headquartered in Atlanta and services nearly 350 destinations in 65 countries, according to SkyTeam. In 2015, Delta was named "Domestic Airline of The Year" by "Travel Weekly." Delta Airlines partners with Air France and Alitalia for its trans-Atlantic flights and has international hubs in Amsterdam and Tokyo.
American Airlines is the primary American carrier for OneWorld. American Airlines operates out of a number of American hubs and services 330 destinations in 50 countries.
There are many websites and online tools that help interested customers find international flights, such as Google.com/flights, Priceline.com, Expedia.com and Kayak.com.