image is not available — United Boeing 737 Newark NYC

The folks at American Airlines' Fort Worth headquarters are probably shaking their heads right about now.

That's because United Airlines just announced 10 new destinations from its O'Hare International Airport (ORD) hub in Chicago, all launching next year.

Six of the 10 destinations are new to travelers from ORD, while four will compete against American.

The unique-to-United destinations include:

Eugene, Oregon
Lynchburg, Virginia
Monterey, California
Paducah, Kentucky
Santa Barbara, California
St. George, Utah

All flights, except for those to Monterey and St. George, will operate daily. The two exceptions will only operate seasonally on Saturdays.

Meanwhile, the other new United routes include regional service to:

Idaho Falls, Idaho
Marquette, Michigan
Rochester, Minnesota
Wausau, Wisconsin

All of these routes, except for Idaho Falls, will operate daily. Idaho Falls will only operate on Saturdays.

Furthermore, United will increase frequencies in several Chicago markets, going from weekend-only to daily service next summer, including Hilton Head, South Carolina; Halifax, Nova Scotia; Sun Valley, Idaho; Nassau in the Bahamas; and Aruba.

Additionally, West Palm Beach, Florida, will go from a seasonal to a year-round market.

All of this growth is unlocked by a gate reallocation process at ORD that recently saw United receive five new gates at the airport through the city's annual reallocation process.

American Airlines, which also operates a hub in Chicago, was unhappy with the way the gate allocation process worked. It argued that there was an "improper trigger" related to ORD's ongoing expansion project in the L gates and that the airport couldn't award new gates until that construction process finished.

American took the city's decision to court, where a judge eventually ruled in favor of United, allowing the airline to proceed with claiming more real estate in the airport.

More gates mean more flights, and more flights mean more relevance. United's move isn't a dagger in American's hub operation at ORD, but it certainly caps American's growth potential from the city in the years ahead.

"United is already flying its busiest schedule in history at O'Hare, and now these additional gates have unlocked new opportunities to intertwine cities across the country, serve more customers in Chicago and strengthen our hometown hub," Patrick Quayle, United's network chief, said in a statement.

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United Airlines’ 10-destination Chicago expansion deals blow to American Airlines