General Grant had selected New Carthage, LA, as the staging point for his army as he maneuvered to cross the Mississippi River below Vicksburg. After Admiral Porter's fleet passed the Vicksburg batteries and rendezvoused with Grant, Federal troops could then be moved upriver to strike the Warrenton batteries below Vicksburg, or down the Mississippi River, where forces could storm the Confederate stronghold of Grand Gulf. New Carthage, however, proved inadequate for staging as flood waters inundated the area between Pointe Clear and New Carthage. General McClernand would search for alternate staging areas, and directed some of his troops to investigate the road around Bayou Vidal.
In the vicinity of Dunbar's Plantation on Mill Bayou, which flowed into Bayou Vidal, Missouri Confederates attempted to dislodge a Federal outpost on April 15, but were checked and driven back. The Federals built a bridge across Bayou Vidal and marched along the east side of the stream.
Significance of New Carthage, Early 1863