Battle of Port Gibson - Background

Background

Grant launched his campaign against Vicksburg, Mississippi, in the spring of 1863, starting his army south from Milliken's Bend on the west side of the Mississippi River. He intended to storm Grand Gulf, while his subordinate Maj. Gen. William T. Sherman deceived the main army in Vicksburg by feigning an assault on the Yazoo Bluffs. Grant would then detach the XIII Corps to Maj. Gen. Nathaniel P. Banks at Port Hudson, Louisiana, while Sherman hurried to join Grant and James B. McPherson for an inland move against the railroad. The Union fleet, however, failed to silence the Confederate batteries at Grand Gulf. Grant then sailed farther south and began crossing at Bruinsburg, Mississippi, on April 30. Sherman's feint against the Yazoo Bluffs—the Battle of Snyder's Bluff—was a complete success, and only a single Confederate brigade was detached south.

The only Confederate cavalry in the area, Wirt Adams's cavalry regiment, had been ordered away to pursue Grierson's raiders, so Maj. Gen. John S. Bowen performed a reconnaissance in force to determine the Federals' intentions. Bowen moved south from Grand Gulf with Green's Brigade and took up a position astride the Rodney road just southwest of Port Gibson near Magnolia Church. A single brigade of reinforcements from Vicksburg under Brig. Gen. Edward D. Tracy arrived later and was posted across the Bruinsburg Road two miles north of Green's position. Baldwin's Brigade arrived later and was positioned in support of Green's Brigade. One-hundred-foot-tall (30 m) hills separated by nearly vertical ravines choked with canebrakes and underbrush rendered Bowen's position tenable, despite the overwhelming Union force headed his way.

The absence of Confederate cavalry would have a major impact on the unfolding campaign. Had Bowen been assured that the Federals were landing at Bruinsburg and not Rodney, he could have taken a position on the bluffs above Bruinsburg, denying Grant's army a bridgehead into the interior. Federal efforts to push rapidly inland were exacerbated by the fact that Maj. Gen. John A. McClernand had forgotten to issue rations to the men. Despite the resulting delay, the Army of the Tennessee moved onto the river bluffs unopposed and pushed rapidly towards Port Gibson. Just after midnight on May 1, advanced elements of the 14th Division under Brig. Gen. Eugene A. Carr engaged Confederate pickets near the Shaifer House. Sporadic skirmishing and artillery fire continued until 3 a.m. Wary of Tracy's Brigade to the north, McClernand posted Brig. Gen. Peter J. Osterhaus's 9th Division facing that direction. Having developed each other's positions, both sides settled down and waited for first light.