I could be wrong but I don’t think the older notes have the series dates printed on them. They do, however, have a facsimile signature of both the residing Secretary of the Treasury and of the Treasurer of the United States. Google one of their names and you should get the date when that person held that office. Then you should have some idea on the age of the bill.
If you google “paper money us dating” one of the first hits is The Official Blackbook Price Guide to United States Paper Money 2010 By Tom Hudgeons, Jr., which is available on Google Books. It has some interesting information in there on how to identify paper money.