The U.S. Government is called a Federal Government because it is at the Federal (or highest) Level, there is no other government above it.
Too many.
To name a relatively tame on, the Environmental Protection Agency which is independent and not attached to any one department.
Our forefathers argued about this for years before penning the Constitution. The main objectives for the US Federal Government, that is all three branches: Executive, Judicial, and Legislative...
there is no division of power in the government