On Thursday, JetBlue announced an expanded set of flights from Reagan National Airport — adding Charleston, S.C., Hartford, Conn. and the Bahamas to its slate of destinations.

Beginning June 19, the airline will offer twice-daily service to Charleston and Hartford, and once-daily year-round service to Nassau. JetBlue also will boost existing service to Tampa, adding a second daily flight beginning July 2.

The additional flights are the result of the American Airlines-USAir merger, which required American to give up at least 104 of its slots — enough for 52 round-trip flights — at National. JetBlue as well as Southwest Airlines were among the beneficiaries. In January, Southwest announced it would more than double its presence at National by the end of the year.

JetBlue officials said they will announce additional details of new flights at National later this year.

As part of their National expansion, JetBlue is offering some special fares. They include fares as low as $30 one-way, including taxes and fees, from DCA to Hartford; $44 one-way from DCA to Charleston; and $99 (U.S. dollars) one-way from DCA to Nassau (that flight is subject to the airline receiving operating authority from the government.) Other nonstop JetBlue destinations departing from Reagan are also part of the sale. Fares are valid for mid-week summer travel between June 24 and July 30, 2014 and must be purchased by today, March 6, 2014.