The material found here can be divided into a number of categories:

 

• Public Domain: Materials such as the United States Constitution, the Federalist Papers, and other historical documents are in the public domain. These can be freely copied in whatever manner you wish. Additional materials, such as the audio readings of the Federalist Papers, have been released by their creators into the public domain.
• Original Material: Original articles and opinion pieces, as well as the original biographies, as well as annotations to public domain material, is licensed under the Creative Commons Attribution-Noncommercial license. This means that you can use the material however you like so long as the use is not commercial and you attribute this site as the source.
• Other Material: Some material on this site has been taken from other sites, such as Wikipedia. When this is done, it is in compliance with the license offered by the source of the material, such as the GNU Free Documentation License.

Generally, if the material is obviously public domain (as will be the case for all of the historical documents), you can do whatever you like. For material either original to this site or another organization, you're probably free to use it as you like for non-commercial use with a note as to where the material originated from.