Major McKinley: William McKinley and the Civil War (Google eBook)
Major McKinley is the first complete account of the Civil War service of President William McKinley, the last of the Civil War veterans to reach the White House and the only one who served in the ranks. McKinley enlisted as a private in the 23rd Ohio Volunteer Infantry (later commanded by another future president, Rutherford B. Hayes) and was the regiment's commissary sergeant when his bravery at the Battle of Antietam led to a commission and an assignment to Hayes's military staff.
McKinley regarded the end of slavery as the significant outcome of the war and valued the contributions of the black soldiers in the Union army. After the war, as a young lawyer and congressman, he defended the rights of freedmen and did so long after others had tired of the cause. He also reached out to former Confederate soldiers in an effort to help restore unity to a divided country. This initiative eventually overshadowed and diminished his advocacy of civil rights.
Drawing on a wide variety of sources, including McKinley's own papers and the diaries and letters of men who served with him, this book presents a new picture of McKinley as a soldier and provides a fresh appreciation of his later life as a veteran in politics.