Capital Airlines was an airline
An airline provides air transport services for traveling passengers and freight. Airlines lease or own their aircraft with which to supply these services and may form partnerships or alliances with other airlines for mutual benefit...
serving the eastern United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
that merged into United Airlines
United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees (which includes the entire holding company United Continental...
in 1961. Its primary hubs were National Airport
Ronald Reagan Washington National Airport
Ronald Reagan Washington National Airport is a public airport located south of downtown Washington, D.C., in Arlington County, Virginia. It is the commercial airport nearest to Washington, D.C. For many decades, it was called Washington National Airport, but this airport was renamed in 1998 to...
near Washington, DC, and Allegheny County Airport
Allegheny County Airport
Allegheny County Airport is located in West Mifflin, Pennsylvania, four miles southeast of the city of Pittsburgh. It is the fifth busiest airport in Pennsylvania following Philadelphia, Pittsburgh, Allentown, and Harrisburg...
near Pittsburgh. In the 1950s it was the largest US domestic carrier after the Big Four (AA-UA-TW-EA). Its headquarters was Washington, DC.