The ‘Anaconda Plan’ for the economic suffocation of the South had two components. First, a naval blockade of the Confederate Atlantic and Gulf coast: by late 1861, this was largely achieved. The next priority was control of the Mississippi River, completing encirclement of the South. Blocking this was New Orleans, the largest city and port in the Confederacy. To realize the masterplan, the Union began to assemble a massive amphibious force at Ship Island in the Mississippi Sound during winter 1861–62. On 18 April, Union Commodore Farragut began an intensive bombardment of Forts Jackson and St Phillip at the mouth of the Mississippi. On the night of 23–24 April, having smeared their craft with mud to prevent detection, the Union armada slipped past the forts and, landing a ground force under General Butler, secured their surrender. With its Confederate defence force fleeing, New Orleans was now defenceless, and occupied on 1 May.