The Civil War Trust preserves battlefields. Please donate!
All battle records: The War of the Rebellion: a Compilation of the Official Records of the Union and Confederate Armies.
TOCWOC — The Order of Civil War Obsessively Compulsed – Informed Amateurs Blog the American Civil War
Son of the South, an amazing resource with every Harpers Weekly from the period.
Hardtack and Coffee by John Billings.