27 March 2007
GoogleBooks has the complete 1865 Army Register online. Compiled by the Adjutant-General, this reference volume lists all staff (by corps) and line (by regiment) officers of the Regular Army along with other ranks/commands to which they were assigned and the date they entered service.
Originally published by the US Government Printing Office (1865), this book was digitized from a copy at the University of Michigan on 10 October 2006. Go Wolverines.
Poor, confused GoogleBooks.