The 35th then detached from the Army of the Potomac and was sent to another and distant department. In March 1863, it had proceeded with the reorganized Ninth Corps to the southwest where its services were much needed. April and May were passed in Kentucky. Thence they were transported down the Mississippi to the vicinity of Vicksburg where they threw up earthworks and defenses. They were now with the Army of the Tennessee under the command of General Grant. Under Sherman, after the surrender of Vicksburg, they marched into the interior of Mississippi in pursuit of the force of General Johnston. After days of toilsome and painful marches with frequent skirmishing and a brief siege, they captured Jackson, the capital of the state. Here the 35th had the honor of being the first regiment to plant its colors within the city, pulling down the rebel ensign from the State House and of throwing to the breeze from that abode of treason the stars and stripes. In this campaign, Private David Phalen died in camp of disease. In August, the regiment almost exactly retraced its steps and on October 1 was in Kentucky.