[36] In December, Garfield was ordered to bring the 42nd to Kentucky, where they joined the Army of the Ohio under Brigadier General Don Carlos Buell.[37]

Buell's command[edit]
Buell quickly assigned Garfield the task of driving Confederate forces out of eastern Kentucky, giving him the 18th Brigade for the campaign, which, besides his own 42nd, included the 40th Ohio Infantry, two Kentucky infantry regiments and two cavalry units.[38] They departed Catlettsburg, Kentucky, in mid-December, advancing through the valley of the Big Sandy River.[38] The march was uneventful until Union forces reached Paintsville, Kentucky, on January 6, 1862, where Garfield's cavalry engaged the rebels at Jenny's Creek.[39] Confederate troops under Brigadier General Humphrey Marshall held the town in numbers roughly equal to Garfield's own, but Garfield positioned his troops so as to deceive Marshall into believing the rebels were outnumbered.[39] Marshall ordered his troops to withdraw to the forks of Middle Creek, on the road to Virginia, and Garfield ordered his troops to take up the pursuit.[40] They attacked the rebel positions on January 9, 1862, in the Battle of Middle Creek, the only pitched battle Garfield commanded personally.