The 155th Infantry is one of only twenty-four currently active Army National Guard units with campaign credits for the War of 1812, and one of only two from a state west of the Appalachians.

It was at the Battle of Buena Vista when other American units began to be overrun by the Mexicans that Col. Davis gave the order, "Stand fast, Mississippians!"

The 155th Infantry arrived at the port of Newport News, Virginia, on 31 December 1918 on the USS Princess Matoika, and was demobilized 23 January 1919 at Camp Beauregard, Louisiana.

The 155th Infantry was inducted into active federal service at Vicksburg on 20 November 1940 and moved to Camp Blanding, Florida, where it arrived on 21 December 1940.

The 1st Battalion (Combined Arms), 155th Infantry (Mechanized) is now a part of the 155th Armored Brigade Combat Team (155th ABCT), Mississippi Army National Guard.