Well, I learned that you can find old records at Archives somewhere near ISD or same location,whatever you can.You can find out where to get very old records copy if you can. The name of my ancestor was Corwin B. Canfield.He never was on census so far.He was supposed to be a deaf student of Iowa School for the Deaf in around early 1870.He was an oldest brother of my great grandmother. Canfield moved to Nebraska after 1870. Try to search from 1870 if you can. Let me know what you can find or not.