PHILADELPHIA (CBS) — An unpublished 1933 letter written by aviation pioneer Amelia Earhart has surfaced for sale in Philadelphia.

Nathan Raab, a principal at the Philadelphia-based Raab Collection, says the letter was recently acquired from a private collector.

He says it was written by Amelia Earhart in August 1933 in response to correspondence from a 13-year-old girl from Detroit who had asked for advice on how she could follow in Earhart’s footsteps.

“It really speaks to the inspirational role that Amelia Earhart played in reaching out to girls and young women at the time when people were looking to advance their careers,” Raab says, “but also to be inspired by somebody who had succeeded in a man’s world.”

Earhart advises the girl to pursue flight lessons if she is sincerely committed because Earhart confides she believes there will someday be opportunities for women as commercial pilots.

“The response is just remarkable,” Raab says. “You get a sense that this was a meaningful letter to her and she explains how you would go about doing what she had done, describing in detail some of the steps that a girl and a woman could take to succeed in aviation to become a pilot.”

The aviatrix also suggested that if flight lessons were a problem, her admirer could get involved on the fringes of aviation such as an air hostess.

Click here to read the letter and to learn more about it: