United Airlines, one of the top 3 legacy carriers in the USA based at Chicago, has been consistently serving millions of customers for the past several decades. Currently the world’s third largest airline in terms of fleet size as well as the number of routes flown, and the founding member of Star Alliance, United Airlines is operating flights to USA and different parts of the globe from its main hub at Chicago O’Hare International Airport (ORD). The airline will also efficiently connect you to various domestic and international destinations from its other secondary hubs such as Denver, Guam, Houston, Los Angeles, Newark, San Francisco and Washington. With United Airlines Reservations you can easily reach 238 domestic destinations and 118 international destinations in 48 countries across five continents.