After left almost 8,000 residents of New Orleans dead, the state again created a Board of Health and made it permanent. The Union Navy's blockade of New Orleans six years later, as the Civil War began, the city for the first time in the century recorded no deaths from yellow fever. When General Benjamin Butler took over control of the city when it fell to Union forces in 1862, he went further, dispatching 2,000 troops to dispose of the city's garbage and instituting a quarantine requirement for arriving ships. At a point down the Mississippi River from the city, all vessels were stopped by gunboats and held for 40 days while they were monitored for disease. There were few deaths from yellow fever in New Orleans for the remainder of the war.