Editing William McKinley (section)

===Shenandoah Valley and promotion===
[[File:McKinleyBrady 1865.png|thumb|upright|McKinley in 1865, just after the Civil War, photograph by [[Mathew Brady]]]]
While the regiment went into winter quarters near [[Charleston, West Virginia|Charleston, Virginia]] (present-day West Virginia), McKinley was ordered back to Ohio with some other sergeants to recruit fresh troops.{{sfn|Armstrong|pp=44–45}} When they arrived in Columbus, Governor [[David Tod]] surprised McKinley with a commission as [[second lieutenant]] in recognition of his service at Antietam.{{sfn|Armstrong|pp=44–45}} McKinley and his comrades saw little action until July 1863, when the division skirmished with [[John Hunt Morgan]]'s cavalry at the [[Battle of Buffington Island]].{{sfnm|Hoogenboom||1pp=157–58|Armstrong||2pp=47–55}} Early in 1864, the Army command structure in West Virginia was reorganized, and the division was assigned to [[George Crook]]'s [[Army of West Virginia]].{{sfnm|Hoogenboom||1pp=162–64|Armstrong||2p=63–65}} They soon resumed the offensive, marching into southwestern Virginia to destroy salt and lead mines used by the enemy.{{sfnm|Hoogenboom||1pp=162–64|Armstrong||2p=63–65}} On May 9, the army engaged Confederate troops at [[Battle of Cloyd's Mountain|Cloyd's Mountain]], where the men charged the enemy entrenchments and drove the rebels from the field.{{sfnm|Hoogenboom||1pp=162–64|Armstrong||2p=63–65}} McKinley later said the combat there was "as desperate as any witnessed during the war".{{sfnm|Hoogenboom||1pp=162–64|Armstrong||2p=63–65}} Following the rout, the Union forces destroyed Confederate supplies and skirmished with the enemy again successfully.{{sfnm|Hoogenboom||1pp=162–64|Armstrong||2p=63–65}}

McKinley and his regiment moved to the [[Shenandoah Valley]] as the armies broke from winter quarters to [[Valley Campaigns of 1864|resume hostilities]]. Crook's corps was attached to [[Major general (United States)|Major General]] [[David Hunter]]'s [[Union Army of the Shenandoah|Army of the Shenandoah]] and soon back in contact with Confederate forces, capturing [[Lexington, Virginia]], on June 11.{{sfnm|Hoogenboom||1pp=166–68|Armstrong||2pp=66–69}} They continued south toward [[Lynchburg, Virginia|Lynchburg]], tearing up railroad track as they advanced.{{sfnm|Hoogenboom||1pp=166–68|Armstrong||2pp=66–69}} Hunter believed the troops at Lynchburg were too powerful, however, and the brigade returned to West Virginia.{{sfnm|Hoogenboom||1pp=166–68|Armstrong||2pp=66–69}} Before the army could make another attempt, Confederate General [[Jubal Early]]'s raid into Maryland forced their recall to the north.{{sfn|Armstrong|pp=70–71}}

Early's army surprised them at [[Second Battle of Kernstown|Kernstown]] on July 24, where McKinley came under heavy fire and the army was defeated.{{sfnm|Hoogenboom||1pp=168–69|Armstrong||2pp=72–73}} Retreating into Maryland, the army was reorganized again: Major General [[Philip Sheridan]] replaced Hunter, and McKinley, who had been promoted to [[Captain (United States O-3)|captain]] after the battle, was transferred to General Crook's staff.{{sfnm|Hoogenboom||1pp=170–71|Armstrong||2pp=75–77}} By August, Early was retreating south in the valley, with Sheridan's army in pursuit.{{sfn|Armstrong|pp=78–80}} They fended off a Confederate assault at [[Battle of Berryville|Berryville]], where McKinley had a horse shot out from under him, and advanced to [[Battle of Opequon|Opequon Creek]], where they broke the enemy lines and pursued them farther south.{{sfnm|Hoogenboom||1pp=172–73|Armstrong||2pp=80–82}} They followed up the victory with another at [[Battle of Fisher's Hill|Fisher's Hill]] on September 22 and were engaged once more at [[Battle of Cedar Creek|Cedar Creek]] on October 19.{{sfn|Armstrong|pp=84–91}} After initially falling back from the Confederate advance, McKinley helped to rally the troops and turn the tide of the battle.{{sfn|Armstrong|pp=84–91}}

After Cedar Creek, the army stayed in the vicinity through election day, when McKinley cast his first presidential ballot, for the incumbent Republican, [[Abraham Lincoln]].{{sfn|Armstrong|pp=84–91}} The next day, they moved north up the valley into winter quarters near Kernstown.{{sfn|Armstrong|pp=84–91}} In February 1865, Crook was captured by Confederate raiders.{{sfn|Armstrong|pp=95–96}} Crook's capture added to the confusion as the army was reorganized for the spring campaign, and McKinley served on the staffs of four different generals over the next fifteen days—Crook, [[John Dunlap Stevenson|John D. Stevenson]], [[Samuel S. Carroll]], and [[Winfield Scott Hancock|Winfield S. Hancock]].{{sfn|Armstrong|pp=95–96}} Finally assigned to Carroll's staff again, McKinley acted as the general's first and only [[adjutant]].{{sfn|Armstrong|pp=98–99}}

Lee and his army [[Battle of Appomattox Court House#Surrender|surrendered]] to [[Lieutenant general (United States)|General]] [[Ulysses S. Grant]] a few days later, effectively ending the war. McKinley joined a [[Freemasonry|Freemason]] lodge (later renamed after him) in [[Winchester, Virginia]], before he and Carroll were transferred to Hancock's First Veterans Corps in Washington.{{sfn|Armstrong|pp=99–101}} Just before the war's end, McKinley received his final promotion, a [[Brevet (military)|brevet]] commission as major.{{sfn|Armstrong|pp=103–05}} In July, the Veterans Corps was mustered out of service, and McKinley and Carroll were relieved of their duties.{{sfn|Armstrong|pp=103–05}} Carroll and Hancock encouraged McKinley to apply for a place in the peacetime army, but he declined and returned to Ohio the following month.{{sfn|Armstrong|pp=103–05}}

McKinley, along with Samuel M. Taylor and James C. Howe, co-authored and published a twelve-volume work, ''Official Roster of the Soldiers of the State of Ohio in the War of the Rebellion, 1861–1866'', published in 1886.<ref>[[#roster|McKinley, Taylor, Howe, 1886]]</ref>