There was a thread on the availability of ACW newspapers online recently in the Usenet newsgroup. Jane Margaret Laight and Donald Plezia contributed these links to that discussion:
North American Review
New York Times
I made use of the Brooklyn Eagle link and was again struck by the North's lack of war coverage.
p.s. (12:48 p.m.) I am remiss in not also linking to Vicki Betts' monster list of newspapers, text searchable by keyword.