When I began researching in U.S. federal census records, I was confused about the naturalization column.  I knew AL was Alien and NA was Naturalized, but what was PA and what documents could I follow on the naturalization process to find out more about a family?

John J. Newman has written the American Naturalization Processes and Procedures 1790 – 1985, which clearly explains the various factors of naturalization.  Changes in naturalization laws over time has made it important to investigate what the requirement was at the time in question.  John also discusses naturalization based on military service and land purchase.

The simple timelines and examples of the forms used over the years make for an excellent reference guide to both beginners and seasoned genealogists.  One less thing to memorize.