[1][2] The Forty-second was organized on May 14, 1862, in the Mississippi Volunteers at Oxford from the counties of Carroll, DeSoto, Tishomingo, Calhoun, Yalobusha, Panola, and Itawamba.

The 42nd Regiment was engaged in fierce fighting during the Gettysburg, taking heavy casualties, with the brigade commander Col. Hugh R. Miller killed in action.

In the aftermath of the Gettysburg campaign, the Regiment fought at the Battle of Bristoe Station after retreating into Virginia.

It lost 46 percent of the 575 engaged at Gettysburg, had eight disabled en route from Pennsylvania, and had six killed and 25 wounded during the Bristoe Campaign.

When the Union forces broke through the Confederate lines at Petersburg in early April, 1865, the remnants of the 42nd Regiment were captured and surrendered.