Aaron Houston for The New York Times The 1787 letter from George Washington, beneath his image in a scrapbook begun in 1826. Aaron Houston for The New York TimesBill Schroh, director of operations at the Liberty Hall Museum, looking at the Washington letter. UNION, N.J., April 26 — The letter from George Washington is pasted between poetry and party invitations, stuffed into a dusty scrapbook amid jokes and cutouts of handsome men, and all the highlights of a lucky little girl’s life. It was written in May 1787 and addressed to Jacob Morris, grandfather of Julia Kean, the precocious...