The acronym DC can mean many things, and context will tell you which one , such as:
The initails fo D.C in Washington D.c is District of Columbia.
Columbia
If you mean George C. Marshall, he died in Washington DC on October 16, 1959.
Obama's Mother in law will be staying with the family in Washington, D C.
The US Capital is Washington DC.
The Capitol Building in Washington, DC
Columbia
Illinois is West North West of Washington DC.
Washington D.C.Washington,D.C.
Washington D.C. is formally known as Washington, District of Columbia. Nowadays, it is usually referred to as simply: Washington, or the District, or simply D.C.
No - DC (District of Columbia) is not a state; it is a Federal enclave.
The address of the Diplomatic Reception Rooms is: 2201 C St NW, Washington, DC 20520
The address of the Diplomatic Rooms Foundation is: 2201 C Street NW, Washington, DC 20520