Grouping the united states into the northeast region, the northwest region, the southeast region, and the southwest region would be departmentalization by

Grouping the united states into various regions would be departmentalization  by location.
Various organizations and entities use the departmentalization based on task, function or service etc. A divide which is based on various locations will be called departmentalization by location as it involves northeast, northwest, southeast and southwest locations.

2018 means 2018 ce or common era

there have been other eras too including bce, which included way more years.

they are best known for the cliff pueblos found throughout arizona, new mexico, colorado and utah. and for their development of desert farming.

hope i

-lavira: )