Footnote's database of genealogical documents has a collection of nearly 69 million items. In connection with the U. S. National Achieves, the Library of Congress and other institutions, they provide many never-before-seen historical documents. All material is in digital format for easy viewing using the Internet.
They cover a wide-range of documents, photos, indexes, directories, census records, naturalization forms, military records and maps from all across the United States. Besides viewing the documents, they can be printed and saved to a computer. Comments in reference to a document or image can be added. That bit of additional information may just be of help to someone researching.
There is a complete search engine for locating people or topics from the many databases. The researcher can also create their own Footnote page, adding images of documents and a photo galley.
The subscription fee-based web site has a monthly and annual membership available with access to the databases. They also have a free membership for viewing the free images and numerous documents. Some examples of free historical documents would be the 1867 court martial trial of George A. Custer, correspondence by George Washington and reports / testimony relating to the President Lincoln assassination. It is possible to add one's own documents and photos to the collection.