Müller was disappointed by the failure of the Prussian Revolution in 1848, and realised there might be implications for his life and career. As a result, he emigrated to South Brazil in 1852, with his brother August and their wives, to join Hermann Blumenau's new colony in the State of Santa Catarina. The colony, near the coast on the Itajaí River, was called Blumenau. In Brazil, Müller, living with his wife Caroline, became a farmer, doctor, teacher and biologist, sometimes employed by the provincial government, sometimes surviving on his own efforts, sometimes defending against Indians but always collecting evidence of life in the Atlantic forest. The climate here is sub-tropical, and the vegetation typical of the Brazilian coast: it is not rain forest.