The United States has been under martial law for some time.
You may protest this statement and to be fair, being "Under Martial Law" is more of a continuum than an easily defined state. The fact is we have been becoming more and more acclimated to military style policing. Additionally, the stage is set, legally for a complete military occupation of our homeland and this occupation is pending.
There have been ongoing military exercises in the U.S. for the last few years...