A letter President John F. Kennedy sent to a little girl who was a big fan is up for grabs in Philadelphia.

A rare documents dealer is selling the short, typed letter to 5-year-old Rita Lynn Knight for $15,000.

The girl's father had written Kennedy to share an anecdote about Rita hoping to use 2 cents to buy a bus ticket to Washington from her home in Louisville, Kentucky.

Kennedy wrote to Rita in response. In the letter, dated March 29, 1962, Kennedy says he's sending it "to surprise you and say 'hello.'"

Raab Collection President Nathan Raab says the correspondence is remarkable because so few letters from Kennedy to children have survived.

The dealer was unable to find any current information on Rita Knight.