Definitions for "occupied"
Engaged; in use; being used by a person and not free for use by someone else; as, the wc is occupied. Opposite of free, available, and unoccupied.
Overrun, taken over; -- of countries or territories; as, occupied France. Opposite of unoccupied.
Busy; actively or fully engaged in some activity; -- of people. Opposite of idle.
Inhabited, lived-in, tenanted; having residents; -- of dwelling units.
resided in; having tenants; "not all the occupied (or tenanted) apartments were well kept up"
property that is being inhabited and properly maintained (i.e., evidence of mail, utilities, grass cuts).
In this sentence, the word occupied means the union soldiers were in charge of Washington, D.C.
Keywords:  filled, held, keeps, well, her
held or filled or in use; "she keeps her time well occupied"; "the wc is occupied"
Keywords:  controlled