This may be one of the most invaluable additions to internet research. Secondary material, things you have written, are another way of getting your point across. This requires you do a great deal of reading, thinking, and then writing on your topic. Another possibility is to use articles by other webmasters to build your site. If you do this, be sure to ask them permission before using their materials.
Pictures are always helpful.
Both modern and Civil War-era pictures may help get your topic across even better, dress up the site, etc.