Fallout shelters are still someone in use but not for the purposes of nuclear fallout, only severe storms, etc. Th Interstate Highway System is the best choice from this list.
Answer: Its economic base was agriculture.
It lacked a modern transportation system. It lacked a substantial wealthy class.
The key waterways in the south during the civil war were: Mississippi,Ohio and Tennessee rivers
Both side aware that controlling these rivers would cut down oppositions food and weaponry supplies along with limiting the opposition's ability to mobilize. The union army managed to leverage on this situation better than the Confederates, leading to the union's victory during the civil war.
