I am writing to urge researchers to pay attention to their state legislatures. In an effort to satisfy privacy concerns legislatures are eliminating access to some personal records no matter how old. In NC we can no longer access records of patients in state hospitals, even if the records are for people who have been dead 100 years. The same goes for state prison records. You may think that restrictions on these kinds of records will not affect you, but believe me, sooner or later you will find that black sheep in your family who was never mentioned at family gatherings.
Check with your state archives. The folks there should know if these open-ended restrictions have been made or are being considered in your state. I think it is just lazy legislating. It's easier just to say these records are restricted period than to figure out how long to keep them under wraps.
If you are in NC, call or write your state legislator today. Seriously, if enough folks contact them they will act.