The Missing Patent
Wilbur and Orville Wright's official patent for their "flying machine," submitted in 1903, is an important slice of American history. The patent was supposed to be stored in the National Archives, where historical treasures are housed. However, in 2000, officials discovered that it seemed to have vanished. Researchers looked through storage vaults, filing cabinets, and archives around the country, to no avail. Some wondered whether the document had been stolen. Finally, Chris Abraham, newly assigned to the National Archives' document recovery program, volunteered to solve the puzzle. Abraham suspected that the patent might have been mistakenly sent to a huge storage facility in Kansas where other, less important patent documents were kept. Abraham was right: after searching through boxes and boxes of documents, he found the patent on March 22, 2016.
What is the main, or central, idea of the passage?