Final answer:
Louisiana is the state most affected by Mississippi River flooding due to its location, pattern of severe past flooding events, and reliance on infrastructure like levees and pumps to manage water flow.
Step-by-step explanation:
The state that would be most affected by the Mississippi River flooding is Louisiana. Due to its location along the lower course of the Mississippi River Louisiana has a history of severe flooding, especially in areas near the river and its delta. For instance Hurricane Katrina in 2005 caused major breaches in the levee system around New Orleans leading to catastrophic flooding and significant loss of life and property.
Besides geographical positioning the state's infrastructure such as levees and pumps, is designed to manage the water levels of the Mississippi River, making it especially vulnerable to flooding events.