Answer:
Answer is Option B: They knew the lower Mississippi River was an important strategic location.
Step-by-step explanation:
Control of the Mississippi River during the American Civil War was a crucial factor for both the North and the South. The river was an essential channel for the farmers who shipped their goods by the Gulf of Mexico to the eastern states.
The Union wanted to capture the Mississippi river along the southern positions. It tried to capture the New Orleans port and move North. They then joined Grant's army and head South of the river. Since it was a good location strategically, Union was interested in Louisiana during Civil war.