The official name of the country has changed as the form of government has changed. The declaration of independence signed on 6 November 1813 by the deputies of the Congress of Anáhuac called the territory ''América Septentrional'' (Northern America); the 1821 Plan of Iguala also used América Septentrional. On two occasions (1821–1823 and 1863–1867), the country was known as  (Mexican Empire). All three federal constitutions (1824, 1857 and 1917, the current constitution) used the name —or the variant , all of which have been translated as "United Mexican States". The phrase , "Mexican Republic", was used in the 1836 Constitutional Laws.