Not much is known about what was probably the only distinctly Scandinavian unit in the Confederate army, the Scandinavian Guards of New Orleans. Its muster roll, with the names of 100 officers and men, is reproduced here. This is the only roll in existence, and was provided by the Military Library, Louisiana National Guard (Jackson Barracks, New Orleans)

In the early months of 1862 (February-April), Governor Thomas O. Moore of Louisiana arranged with Maj. Gen. Mansfield Lovell, commanding Department No. 1 (primarily the defenses of New Orleans), to transfer two brigades of militiamen to Confederate service. Lovell accepted 11 regiments and 2 battalions of "Volunteer State Troops" (including the Chalmette Regiment). These regiments were to be mustered into 90 days national service only, under the command of state Brig. Genls. Benjamin Buisson and Edward Tracy. The Chalmette Regiment entered Confederate service on 25 February 62, as part of Buisson's 1st Brigade.

In April 1862, Lovell organized the defenses of New Orleans into two districts; the Coast Defenses (exterior lines) under Brig. Gen.. Johnson K. Duncan, and the Chalmette-McGehee Defenses (interior lines) under Brig. Gen. Martin L. Smith. Buisson's 1780 poorly armed state volunteers were assigned to Smith's command. On April 5, the Chalmette Regiment, with a strength of about 500 men, arrived at Quarantine Station, about 5 miles above Forts Saint Philip and Jackson, to guard the approaches to the city from the sea through the bayous and canals, on both sides of the river. Shortly afterwards, however, unprecedented high water dislogded many of the troops, who had to be removed to the west bank. Company D was detached to man the water battery at Fort Saint Philip.

On 18 April the Union Navy began a six-day bombardment of Forts St. Philip and Jackson. Then, on 24 April, the Federal fleet blasted past the forts and landed 18000 men on the eastern shore, near Fort St. Philip. The entire Chalmette Regiment (except Company D) was captured and paroled at Quarantine Station on 24 April 1862.

Lieutenant George H. Perkins of the USS Cayuga described the scene in a letter dated New Orleans, April 27, 1862:
"..The Cayuga still led the way up the river and at daylight we discovered a regiment of infantry encamped on shore. As we were very close in, I shouted to them to come on board and deliver up their arms, or we would blow them all to pieces. It seemed rather odd for a regiment on shore to be surrendering to a ship! They hauled down their colors, and the Colonel and command came on board and gave themselves up as prisoners of war. The regiment was called the Chalmette Regiment, and has been quite a famous one. The officers were released on parole and allowed to retain their sidearms, all except one Captain, who I discovered was from New Hampshire..."

At the military court of inquiry assembled in Jackson, Miss., to investigate the fall of New Orleans, Colonel Szymanski made the following statement when asked about the surrender of his regiment (April 18, 1863):
"When the forts were passed, just about break of day, the fleet came upon my small camp and opened fire. After losing some 30 men killed and wounded, without a possibility of escape or rescue- perfectly at the mercy of the enemy, he being able to cut the levee and drown me out- I thought it my duty to surrender. A single shell could have cut the light embankment."

Later, when Union Maj. Gen. Benjamin F. Butler assumed command in New Orleans, the officers and men of the Volunteer State Troops residing in the city were arrested as prisoners of war, and those who did not take the loyalty oath were exchanged on 8 October 62 near Vicksburg, Miss. The majority did take the oath, but a number enlisted in Confederate Louisiana units serving in the Vicksburg area.