The major threats, foreign and domestic, that the United States has confronted in the Post Cold-War Era after 9/11.

Domestic- Possible Terrorist threats inside of the country(ghost cells), also large lockdown on foreign immigration and airplane security. Outside the US, non direct war in Afghanistan and Middle East, vs Russian Backing and terrorist organizations like ISIS and Al-Queda, the first is far more lethal to American Assets

Explanation:

war of 1812  

a. slavery

b. a depression  

c. impressment  

d. the northwest ord

that would be the steamboat because none of the other things are forms of transportation