<Tr> <Td> Yucatán (state) </Td> <Td> </Td> </Tr> <Tr> <Td_colspan="2"> Today part of </Td> <Td> Mexico Belize </Td> </Tr> <P> The Republic of Yucatán (Spanish: República de Yucatán) was a sovereign state during two periods of the nineteenth century . The first Republic of Yucatán, founded May 29, 1823, willingly joined the Mexican federation as the Federated Republic of Yucatán on December 23, 1823, less than seven months later . The second Republic of Yucatán began in 1841, with its declaration of independence from the Mexican Federation . It remained independent for seven years, after which it rejoined the Mexican Federation . The area of the former republic includes the modern Mexican states of Yucatán, Campeche and Quintana Roo . The Republic of Yucatán usually refers to the Second Republic (1841--1848). </P> <P> The Republic of Yucatán was governed by the Constitution of 1841, one of the most advanced of its time . It guaranteed individual rights, religious freedom and what was then a new legal form called amparo (English: protection). The 1847 Caste War caused the Republic of Yucatán to request military aid from Mexico . This was given on the condition that the Republic rejoin the Mexican Federation . </P>

When did the república de yucatán declare independence from mexico