One of the things I am fascinated with is the Ohio "100 days Men"
The principal person behind the 100 days regiments was Ohio governor, John Brough. He visited Washington and offered President Lincoln 30,000 (in the end 38,000) Ohio men for a hundred days. Four other western states (Indiana, Illinois, Iowa and Wisconsin) also raised regiments. The 100 days men were meant to serves as guards for bridges, fort and railroads thereby releasing the soldiers to mop up the war but many ended up in the thick of battle. While ending the war in 100 days was a noble idea and an ambitious plan; its failure was by no means the fault of the men who served. In the end, the regiments did far more than was expected of them.
There are several good books that speak to this unique part of history.
History of the 133 regiment. O.V.I. and Incidents Connected with its Service During the "War of the Rebellion", by the Historian of the Association of its survivors, S. M. Sherman, M.D. 1896
A Hundred Days to Richmond: Ohio's "Hundred Days" Men in the Civil War, Jim Leeke, 1999.