Why were levees built along the Mississippi River in 1900?

New settlers adopted aggressive flood-control tactics to protect their new settlements from inundation. Rather than only settling those lands less susceptible to overflow, the new frontiersmen also reclaimed lands well within the floodplain and constructed levees to protect them.

well the fact it is basically a peninsula allowed trade to come from many places, thus allowing cultural diffusion to take place. india has seasonal monsoons that merchants travel back and forth from india using the monsoons wind patterns