During the first year of the Civil War, the southern ports in the Gulf of Mexico were sites of frequent blockade-running activity. In the first ten months, New Orleans, Louisiana, the largest cotton port in the world, gave port to more than 300 blockade runners. When New Orleans fell to Union forces on April 25, 1862, the center for blockade-running activity shifted to Mobile, Alabama. Once New Orleans and the Mississippi River were secured, the Union Navy increased its blockade of Mobile, Alabama and other ports along the Gulf coast, forcing blockade runners to shift to the port at Galveston, Texas, especially after the summer of 1864. Blockade runners used Havana as a stopover point, for transferring cargoes to and from neutral ships.