She was then transferred to the mouth of the Mississippi River in early 1862, as part of a force tasked with neutralizing Confederate forts guarding New Orleans, Louisiana.

According to naval historian Paul Silverstone, the schooner Maria J. Carlton had been built in Philadelphia, Pennsylvania, before the American Civil War and launched at an unknown date.

[4] After her commissioning, Maria J. Carlton was assigned to the Mortar Flotilla, which was tasked with helping neutralize Confederate forts guarding New Orleans, Louisiana, which was the largest and wealthiest city in the Confederacy.

In mid-February, she began moving towards the mouth of the Mississippi River, and lost her mainmast, rigging, and sails in a gale off of Cape Hatteras.

[4] Using a jury mast, the vessel was able to make it to Key West, where she joined the Mortar Flotilla under David Dixon Porter by March 2.

[5] Traveling via Ship Island,[6] Maria J. Carlton moved through Pass a Loutre on March 18, and entered the Mississippi River Delta,[4] working with only one mast.

[12] Maria J. Carlton was the only Union warship sunk solely by artillery fire from Confederate forts on the Mississippi River during the war.