What did Wilbur Wright include in his letter to the Smithsonian Institute as noted in the biography, The Wright Brothers?

On May 30, 1899, Wilbur was home alone and was fidgety; he wanted to do more with his time than repair and sell bikes. He wrote the most important letter of his life that day. The letter, in fact, was one of the most important in history. It was addressed to the Smithsonian Institute in Washington, D.C. He explained that he had a long-time interest in flight – mechanical and human. He wrote that after exhaustive study, he had concluded that human flight was possible. He asked for all the information that the Smithsonian had on the subject. The institute responded by sending all the available literature they had on the subject. There was no offer from the Institute to provide the Wrights with any monetary sponsorship for their pursuit. However, the material that Wilbur was sent helped to invigorate the interest that he and Orville had in aviation and launched their pursuit of a flying machine.