Shortly after "Louisiana" was launched, the Federal West Gulf Blockading Squadron, under Flag Officer (later Admiral) David G. Farragut had moved into the lower Mississippi River, threatening the Confederate-held Forts Jackson and St. Philip, about 120 kilometers or 75 miles below New Orleans. A portion of the squadron, a division of mortar boats led by Commander (later Admiral) David Dixon Porter, had on 16 April 1862 taken position downstream, and on 18 April they began their bombardment. Brigadier General Johnson K. Duncan, commanding the forts, and his immediate superior officer, Major General Mansfield Lovell, importuned Commander William C. Whittle, in charge of Confederate naval forces in the vicinity, to bring the ship down to the forts, even though she was not yet complete, and for that reason was still in the hands of her builders. Whittle yielded to their pleas, and on 20 April commissioned the vessel in the CS Navy, with Commander Charles F. McIntosh commanding.