D.C. Code § 1-102: District created body corporate for municipal purposes.

The District is created a government by the name of the “District of Columbia,” by which name it is constituted a body corporate for municipal purposes, and may contract and be contracted with, sue and be sued, plead and be impleaded, have a seal, and exercise all other powers of a municipal corporation not inconsistent with the Constitution and laws of the United States and the provisions of this Code.