In which war did america experience s a direct military attack upon its own territory

There are many wars (if you think about it ) where the US territory was attacked. Here are a few.

Revolutionary War: Mainly fought in the 13 colonies (which was the US during the time) 
Mexican American War: Fought in present-day mainland US's western half
World War II: US joined the war because its state Hawaii was attacked
Iraqi War (war on terror): Fought because terrorists attacked US home soil (includes twin tower, Pentagon, etc)

these are a few that i can think of 

hope this helps