The Article of Admission of the Constitution of the Kingdom of the United Provinces of Brazil, found at Article XI, authorizes the Congress to admit new territories into Brazil as federative units.
Since the ratification of the Constitution in 1824: 17 new federative units were admitted to the Union. Of these:
- 7 were conquered by war or in treaties that ended a war (Corrientes, Ecuador, Ucayali, Acre, Corrientes, Western Guyana and Eastern Guyana);
- 9 were admited by diplomacy (Uruguay, New Scandinavia, Patagonia, Cozumel, Brazilian Polynesia, Zenith, Cádiz, Socotra and Jeju);
- one was bought from another country (Surinam);
- 7 were Brazil's ex-colonies (New Scandinavia, Cozumel, Brazilian Polynesia, Zenith, Socotra, Jeju and Singapore);
- two withdrew the federation by war (Uruguay) or diplomacy (Singapore);
- and one returned to the Union after withdrawing (Uruguay).
Of the 17 federative units admitted by the Congress, 7 have been established from an existing Brazilian Federal Territory.