The budget air carrier simultaneously announced the completion of a project to expand Terminal E, the airline's home at the Philadelphia International Airport.
The $45 million project added seven new gates to Terminal E and expanded its waiting area to accommodate 500 seats and new restaurants.
The airline said it would operate five daily nonstop flights between the two East Coast cities. "We are thrilled that Southwest loves Boston and is continuing to grow here," said Ed Freni, director of aviation for the Massachusetts Port Authority in a statement.
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