The Edwards Air Force Base, Which was built in Kern County, California in 1933, was originally used as an aircraft test bombing range. During WWII, the base became the site of most of the domestic bombing and of flight testing within the continental United States.

The Air Force Flight Test Center, within the base, continues to serve as a location for modern aircraft to be tested. The Andrews Air Force Base hosts the Air Force Flight Test Center Musuem within its grounds.
Author’s Note:
The NASA Space Agency works in conjunction with the U.S. Air Force at Andrews Air Force Base in regards to aviation experiments.