Next time you happen to be in Ithaca, you may want to stop by Cornell University Library’s Division of Rare and Manuscript Collections, because they now host The Stewart O’Nan Papers, 1987-2009. The abstract:
Records documenting the work of writer Stewart O’Nan including manuscripts, books, research files and correspondence with publishers and other writers. The collection includes his research, drafts, and correspondence during the writing process for his varied books as well as additional correspondence and material. Papers from the following books are included, Gardner Book, Snow Angels, The Names of the Dead, Dear Stephen King, The Speed Queen, The War Back Home / A World Away, A Good Day to Die / Cuba Libre, The Vietnam Reader, A Prayer for the Dying, The Circus Fire, Everyday People, Summer People, Wish You Were Here, The Night Country, Upstate / The Good Wife, Faithful, Last Night at the Lobster, Songs for the Missing, and Clara (Screenplay).
The Works of Stewart O'Nan 
As an archivist, I can say that I am envious of whatever archivist at Cornell gets the pleasure of cataloging your papers!