Answer:
Commander In Cheif: President Abraham Lincoln (1861–1865) President Andrew Johnson (1865)
Commander General:MG Winfield Scott (1841–1861) MG George B. McClellan (1861–1862) MG Henry W. Halleck (1862–1864) GA Ulysses S. Grant (1864–1869)
Explanation:
Congress lacked authority, they could not protect trade between foreign nations and other states.
The success of "Manifest Destiny" encouraged imperialists' ambitions
