The soldiers at Fort Jesup, located just outside New Orleans, had a saying: “Mud and water reach to the boot tops, mosquitoes cover everything above.” The fact that yellow fever was transmitted by the bite of a mosquito was unknown in 1847 and remained so for another fifty years.
Epidemics raged off and on in New Orleans for more than one hundred and fifty years. Yellow fever was joined by cholera in an epidemic in 1832-33. Ten thousand people were known to have died, one in every eight inhabitants. Five hundred died in one day at the peak of the dual epidemics.
The peak of dying during the 1847 epidemic was reached in August, when twenty-two hundred people died. By the first of October, the number of deaths had decreased to a rate of eighty per month. In total some eight thousand people died.
The year of 1853 saw a resurgence of the yellow fever, and seven thousand two hundred citizens died.
Even with all the dying, the population of New Orleans swelled rapidly. At times it grew by more than a thousand a week as shipload after shipload of new immigrants arrived from a score of foreign lands.