I had with me the 13th corps, General McClernand commanding, and two brigades of Logan’s division of the 17th corps, General McPherson commanding—­in all not more than twenty thousand men to commence the campaign with.  These were soon reinforced by the remaining brigade of Logan’s division and Crocker’s division of the 17th corps.  On the 7th of May I was further reinforced by Sherman with two divisions of his, the 15th corps.  My total force was then about thirty-three thousand men.

The enemy occupied Grand Gulf, Haines’ Bluff and Jackson with a force of nearly sixty thousand men.  Jackson is fifty miles east of Vicksburg and is connected with it by a railroad.  My first problem was to capture Grand Gulf to use as a base.

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, and were ready to take position upon the battlefield whenever the 13th corps could be got out of the way.

The country in this part of Mississippi stands on edge, as it were, the roads running along the ridges except when they occasionally pass from one ridge to another.  Where there are no clearings the sides of the hills are covered with a very heavy growth of timber and with undergrowth, and the ravines are filled with vines and canebrakes, almost impenetrable.  This makes it easy for an inferior force to delay, if not defeat, a far superior one.