It was only a little over a decade ago when one had to visit the National Archives, one of it's regional branches or a large and specialized genealogy library to be able to review census records. How times have changed. Today we have come to expect to be able to review census records in more than 2,000 libraries who subscribe to Ancestry Library Edition or even from the comforts of home if one is fortunate enough to have a personal subscription to Ancestry. In addition, Footnote.com is in the process of opening a wealth of other documents to armchair researchers. One thing for researchers to remember is that documents created by the federal government are not protected by copyright as they are considered to be in the public domain.
I will not pretend to describe all the resources available at the National Archives. I would suggest that your exploration begin but not be restricted to the page on Resources for Genealogists and Family Historians. Also visit Inside the Vaults - The Declaration of Independence to see a short video about the document which celebrates its 234th birthday today.
HAPPY BIRTHDAY DECLARATION OF INDEPENDENCE!