Since 1920, the Clerk of the House has compiled and published the official vote counts for federal elections from the official sources among the various states and territories.
House vacancies can be caused by death, resignation, declination, withdrawal, or House action, but the Constitution requires that they be filled by election. The charts detail the vacancies that have occurred and subsequent actions.
Since the start of the modern party system in 1856, the House of Representatives has changed majority 19 times.
State delegations to the House vary greatly in size. Article I, Section II of the Constitution guarantees each state at least one Representative in the House; the total size of its delegation is determined by population. This chart lists the last time that each state’s House delegation had a Democratic majority and a Republican majority. It also lists the last time, if any, that a state’s House delegation was composed entirely of Members of one party.