Footnote.com has opened up all their content relating to the Civil War for free access throughout June. From their website:
Footnote.com has worked with the US National Archives to bring millions of original records to the Internet for the first time. Civil War records that feature everything from personal accounts to historic writings that would shape a nation. Explore vivid details of Civil War battles through maps and photos. Get a personal picture of the war through Union and Confederate soldier service records, pension files, and more.
Go to http://go.footnote.com/civilwar_records/ to search and browse the collection of records, photos, maps, and documents.