Which reference is a primary source document of the Civil War?
A. a biography of Ulysses S Grant
B.a battlefield map drawn by a Soldier serving at the Battle of Gettysburg
C. an encyclopedia article about the North's advantages during the war
D. a book on the effects of the Civil War on the south
(☞ ͡° ͜ʖ ͡°)☞ Please answer if you can