During the night of May 15, 1863, Union
Maj. Gen. Ulysses S. Grant, who was at Clinton, ordered his army to
concentrate at Bolton, because he assumed that Confederate Lt. Gen.
John C. Pemberton would march his Vicksburg army by the most direct
route from Edwards through Bolton to Clinton.
Union Maj. Gen. John A. McClernand's
XIII Corps with Brig. Gen. Peter Osterhaus' division, arrived at Bolton
shortly after 8:00 a.m. after an uneventful march from Raymond. The
force was preceded by several minutes by a detachment of the 3rd Illinois
Cavalry, which captured a few troopers of the Confederate 20th Mounted
Infantry who were loafing near the depot instead of scouting. Osterhaus
immediately ordered the destruction of the Southern Railroad of Mississippi
for a mile in both directions, including all bridges and culverts. Osterhaus
also picked up rumors that there was a large Confederate concentration
at Edwards, some 8.5 miles to the west.
Brig. Gen. Alvin Hovey's division arrived
from the direction of Clinton during the early afternoon (they had marched
north from their bivouac on Baker's Creek to Clinton, and then followed
the Jackson road to Bolton, a total distance of about 12 road miles).
As soon as Hovey's division arrived, McClernand, with Osterhaus' division,
marched on the Bolton road toward its junction with the Middle road,
3 miles to the south.
Union Maj. Gen. James B. McPherson's
XVII Corps , along with the divisions of Maj. Gen. John A. Logan and
Brig. Gen. Marcellus M. Crocker, marched at dawn on May 15 from their
camps around the Deaf and Dumb Asylum in Jackson. By late afternoon
this force had reached camp grounds just east of Bolton.