The Union's strategy was devised by Winfield Scott, whose "Anaconda Plan" called for the division of the Confederacy by seizing control of the Mississippi River. One of the first steps in such operations was the imposition of the Union blockade. After the blockade was established, a Confederate naval counterattack attempted to drive off the Union navy, resulting in the Battle of the Head of Passes. The Union countermove was to enter the mouth of the Mississippi River, ascend to New Orleans and capture the city, closing off the mouth of the Mississippi to Confederate shipping both from the Gulf and from Mississippi River ports still used by Confederate vessels. In mid-January 1862, Flag Officer David G. Farragut had undertaken this enterprise with his West Gulf Blockading Squadron. The way was soon open except the water passage past the two masonry forts held by Confederate artillery, Fort Jackson and Fort St. Philip, which were above the Head of Passes approximately downriver below New Orleans.