OSS, CIA roots, from the office manager of their first headquarters through to their expansion into Europe during WW2, heiress (plantation owner) Gertrude Legendre. She kept detailed journals of her very active life, including financial and legal documents, photos and letters, all of which is considered one of the best resources of American history during the 1900's.
Attached image is a page from the recently published book, A Guest Of The Reich, by Peter Finn about Gertrude Legendre as the first American woman in uniform (rank of Army officer, given without going through officer training) taken prisoner by German forces during WW2.