Why did northern strategists view the mississippi river and its tributaries as vital to a union victory in the civil war?

Ineed a summary over thurgood marshall ! me

From the soviet point of view, which reagan policy most threatened to create a new arms race? a. strategic defense initiative b. u.s. support for israel c. aid to the anti-soviet rebels in afghanistan d. iran-contra scandal

Hitler hoped the threat of would deter the u.s. from entering the war. a. japanb. genocide c. nuclear war d. war on two fronts