The Battle of Grand Gulf was fought on April 29, 1863, during th: By late March, further attempts to bypass Vicksburg had failed.[9]  Grant then considered three plans: to withdraw to Memphis and retry the overland route through northern Mississippi; to move south along the west side of the Mississippi River, cross below Vicksburg, and then strike for the city; or to make an amphibious assault across the river directly against Vicksburg.  An assault across the river risked heavy casualties, and a withdrawal to Memphis could be politically disastrous if the public perceived such a movement as a retreat. Grant then decided upon the downstream crossing.[10]  The advance along the west bank of the Mississippi began on March 29, and was spearheaded by Major General John A. McClernand's troops.[11]  The movement down the river was masked by decoy operations such as Steele's Greenville expedition,[12] Streight's Raid, and Grierson's Raid.[13]  Confederate regional commander John C. Pemberton fell for the Union decoys (especially Grierson's Raid), and lost touch with the true tactical situation, believing Grant was withdrawing.[14]