In early March 1864, the regiment was detached from the Army of the Tennessee and joined the Department of the Gulf under General Nathaniel P. Banks. They were loaded aboard a steamboat and transported down the Mississippi River to the mouth of the Red River in Louisiana. Under their brigade commander, Colonel Lyman M. Ward, they participated in an expedition known as the Red River Campaign. On March 14 they participated in the Battle of Fort De Russy with only a few casualties. Union commanders ordered the fort destroyed by explosives, but nobody told the 95th Illinois and other regiments that were camped nearby. When the fort exploded several members of the regiment were seriously injured and one man killed by falling debris. They continued marching into central Louisiana but did not take part in the principal engagements of the campaign, the Battle of Pleasant Hill and the Battle of Mansfield. The Red River Campaign proved to be a Union disaster and the entire force was compelled to beat a hasty retreat before the falling water level in the Red River stranded their steamboats. During this time the 95th saw action at the Battle of Yellow Bayou. They returned to Vicksburg on April 23 and then were transferred to Memphis.