This Civil War study is based around letters written by a Union Civil War soldier named Daniel Parker.  These letters are currently housed online at the University of Northern Colorado’s Digital UNC collection.  They can be found at 
http://digitalunc.coalliance.org/fedora/repository/cogru%3A4460

These amazing primary source documents were donated to the the University of Northern Colorado’s Library of Congress Teaching with Primary Sources program by a relative of Daniel Parker.