Article: Washington, D.C. is often mentioned as a candidate for statehood. In Federalist No. 43 of The Federalist Papers, James Madison considered the implications of the definition of the "seat of government" found in the United States Constitution. Although he noted potential conflicts of interest, and the need for a "municipal legislature for local purposes," Madison did not address the district's role in national voting. Legal scholars disagree on whether a simple act of Congress can admit the District as a state, due to its status as the seat of government of the United States, which Article I, Section 8 of the Constitution requires to be under the exclusive jurisdiction of Congress; depending on the interpretation of this text, admission of the full District as a state may require a Constitutional amendment, which is much more difficult to enact. However, the Constitution does not set a minimum size for the District. Its size has already changed once before, when Virginia reclaimed the portion of the District south of the Potomac. So the constitutional requirement for a federal district can be satisfied by reducing its size to the small central core of government buildings and monuments, giving the rest of the territory to the new state.

Now answer this question: What caused the size of Washington, D.C. to change?
Virginia reclaimed the portion of the District south of the Potomac