20inch x 30inch Poster Following the passage of forts Jackson and St. Philip, near the mouth of the Mississippi River, on April 24, 1862, the Union occupation of New Orleans was inevitable. Union Flag-Officer David G. Farragut, with his squadron, continued up the Mississippi River and demanded the surrender of the City of New Orleans the next day. The city surrendered on April 28. On May 1, Maj. Gen. Benjamin Franklin Butler??s army began landing at New Orleans and occupying the city. New Orleans, considered an international city and the largest city in the Confederacy, had fallen. There is a border around the image. The image size is correct.