Murder at Fenway Park, by Troy Soos. The first in a series of "Mickey Rawlings" baseball murder mysteries. I read them all. Great use of actual players and baseball atmosphere from the 1910's and 1920's. This is the kind of baseball fiction I would like to write myself.
The Killer Angels by Michael Shaara (1974). Incredibly powerful novel recounting the Battle of Gettysburg. A great book, whether the subject matter interests you or not. Read it, if for no other reason, than for the joy of being introduced to the amazing Joshua Lawrence Chamberlain. You will be glad you met him.