The federal govt has the power to maintain a military
<h3>he stressed the necessity for the United States and Britain to act as the guardians of peace and stability against the menace of Soviet communism, which had lowered an “iron curtain” ...</h3>
Explanation:
<h2>#CARETOLEARN❤️</h2>
1. gulf of tonkin incident
2. truman doctrine
3.containment of communism
probably a little off but it'll lead you in the right direction.
(I was literally learning this a couple months ago and my memory is a little rusty)
The significance was that these allowed goods to be transported much faster than by horse. Canals allowed for things to be imported and exported much more easily.