The Piatt Family Papers are a collection of historical documents that belong to the Piatt family, who were prominent figures in American history. This collection includes letters, diaries, and other personal papers that provide insights into the family's life and their involvement in significant events, particularly during the 19th century. These papers are housed in various archives, including the Ohio Historical Society and the Library of Congress. They serve as valuable resources for researchers studying the social, political, and cultural aspects of the time, as well as the family's connections to notable figures such as Ulysses S. Grant and William Howard Taft.