Its mission is to provide command and control of expeditionary units as directed by the Commander, USAFE.

Like all marine expeditionary units, the force is designed to sustain itself for at least 30 days ashore.

There were two types of units: the expeditionary units created in Spain and militias created in the Americas.

Members of the expeditionary units routinely travel with artillery, 155 millimeter Howitzers that have a range of 10 miles - 18 miles with rocket-assisted projectiles.

The Llaneros were either demobilized or incorporated into the expeditionary units.

After returning to the United States, Decker served as an infantry company commander and later as assistant operations officer for an expeditionary unit in Honduras.

In 2008 it was converted to an expeditionary unit on provisional status for activation by Air Combat Command any time after 28 October 2008.

Both types of historian, uniformed and civilian, can be deployed to an expeditionary unit to collect data and record events as they occur.

Marines operate as expeditionary units and are completely amphibious.

The expeditionary units, each with about 2,000 marines, are used when small forces must be sent abroad quickly for special missions, like rescuing embassy personnel.