D.C. Code § 49-405
Whenever it shall be necessary to call out any portion of the enrolled militia the Commander-in-Chief shall order out, by draft or otherwise, or accept as volunteers as many as required. Every member of the enrolled militia who volunteers, or who is ordered out or drafted under the provisions of this chapter, who does not appear at the time and place designated, may be arrested by order of the Commanding General and be tried and punished by a court-martial. The portion of the enrolled militia ordered out or accepted shall be mustered into service for such period as may be required, and the Commanding General may assign them to existing organizations of the active militia, or may organize them as the exigencies of the occasion may require.
D.C. Code § 49-405