Lincoln grew impatient with McClellan for other reasons — the general's cautious approach to the war and failure to pursue Confederate Gen. Robert E. Lee's army after the bloody 1862 battle of Antietam in Maryland.
Styple was researching a biography of his New Jersey hometown's namesake — Union Gen. Philip Kearny, killed in another 1862 battle — when he found letters and accounts that led to his interest in Thomas Key.
Kearny wrote that McClellan or others with him were "devising a game of politics, rather than war." Styple's book, "McClellan's Other Story," suggests that Key, serving as McClellan's "confidential aide," had unauthorized talks with Confederates and was more interested in protecting McClellan's political ambitions than crushing the Confederate army.
During the war, Lincoln worried about what he called "the fire in the rear" — opposition within the North. Vallandigham led Peace Democrats, or Copperheads, in Ohio, denouncing "King Lincoln" until he was finally arrested and exiled by Lincoln to the South. He made his way to Canada and was the Democrats' nominee for Ohio governor in 1863.
Chase, Lincoln's treasury secretary and former Ohio governor, returned to Ohio to campaign for the pro-Union candidate John Brough, Goodwin writes. When Brough won in a landslide, Lincoln wired his congratulations: "Glory to God in the highest. Ohio has saved the Nation."
McClellan jumped into politics as the 1864 Democratic presidential candidate, with Cincinnati Congressman George Pendleton as his running mate. Union battlefield victories including the Sherman-led capture of Atlanta rallied support for Lincoln in the North and among the troops, and he handily carried Ohio with 56 percent of the vote in his re-election.
Lincoln thus kept up what would become a historical trend that he began when elected the nation's 16th president in 1860 — that a Republican presidential candidate has never won the White House without winning Ohio.
That trend continues today, after Republican nominee Romney's loss to Democrat Obama in Ohio, a state both sides made a focal point of their 2012 campaign.
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