"War at the best, is terrible, and this war of ours, in its magnitude and in its duration, is one of the most terrible."
--Abraham Lincoln, June 16, 1864 Speech at Philadelphia
Archives are a good place to search for primary resources, including photographs! This column has many archival websites for you to search.
This column of websites, databases, and reference material may be helpful, but it may be harder to find primary sources on these.