The 155th Armored Brigade Combat Team is the largest unit in the Mississippi National Guard with approximately 3,500 Soldiers. The "Dixie Thunder" brigade is headquartered in Tupelo and contains subordinate units covering the entire Magnolia State. The unit’s infantry battalion traces its lineage back to 1798 when the 1st Mississippi Regiment was raised. Today, the 1st Battalion, 155th Infantry Regiment carries on this legacy and is the seventh-oldest Infantry regiment in the U.S. Along with the 1-155th Infantry Regiment, the ABCT contains a brigade support, fires, special troops and two combined arms battalions (armor and infantry). The unit also possesses an armored reconnaissance squadron as well.