James Birney begins publishing The Philanthropist, an abolition newspaper named for an earlier abolition newspaper for which Birney had written. The paper was published in Cincinnati, across the Ohio River from Kentucky, a slave state
George McClellan [US] appointed Commander, Department of Ohio. The following day he is promoted major general, his rank in the Ohio militia. Only General-in-Chief Winfield Scott held a higher rank
The term Copperhead is used for the first time in writing by the Cincinnati Gazette. It was used to indicate people who would not admit they were Southern sympathizers, and "peace at any price" Democrats. People who did admit Southern sympathies were called "dough-heads." The paper used the term when refering to members of the Indiana Democratic Convention
While crossing the Ohio River into Kentucky at Buffington Island, John Hunt Morgan's raiders stumble onto a fortified position. Federals manage to kill or wound 120 and capture 700 men and most of the rest return to Ohio to find an alternate crossing.
A small convention in Cleveland of Republican abolitionists unhappy with Lincoln's Emancipation Proclamation and other things, nominates John C. Fremont for president.
Ohio rescinds its ratification of the 14th Amendment when the Peace Democrats gain control of the legislature. The Federal government refuses to recognize the action and counts Ohio as for ratification
The three-day Republican Convention in Cincinnati, Ohio (Hayes home state) shifted its support from front runner James Blaine to Rutherford B. Hayes on the second ballot.