Bruinsburg is two miles from high ground. The bottom at that point is
higher than most of the low land in the valley of the Mississippi, and a
good road leads to the bluff. It was natural to expect the garrison
from Grand Gulf to come out to meet us and prevent, if they could, our
reaching this solid base. Bayou Pierre enters the Mississippi just
above Bruinsburg and, as it is a navigable stream and was high at the
time, in order to intercept us they had to go by Port Gibson, the
nearest point where there was a bridge to cross upon. This more than
doubled the distance from Grand Gulf to the high land back of
Bruinsburg. No time was to be lost in securing this foothold. Our
transportation was not sufficient to move all the army across the river
at one trip, or even two; but the landing of the 13th corps and one
division of the 17th was effected during the day, April 30th, and early
evening. McClernand was advanced as soon as ammunition and two days'
rations (to last five) could be issued to his men. The bluffs were
reached an hour before sunset and McClernand was pushed on, hoping to
reach Port Gibson and save the bridge spanning the Bayou Pierre before
the enemy could get there; for crossing a stream in the presence of an
enemy is always difficult. Port Gibson, too, is the starting point of
roads to Grand Gulf, Vicksburg and Jackson.

McClernand's advance met the enemy about five miles west of Port Gibson
at Thompson's plantation. There was some firing during the night, but
nothing rising to the dignity of a battle until daylight. The enemy had
taken a strong natural position with most of the Grand Gulf garrison,
numbering about seven or eight thousand men, under General Bowen. His
hope was to hold me in check until reinforcements under Loring could
reach him from Vicksburg; but Loring did not come in time to render much
assistance south of Port Gibson. Two brigades of McPherson's corps
followed McClernand as fast as rations and ammunition could be issued,