In 1935, Johnson flew from
Milwaukee to
Fortaleza, Ceará, Brazil, in an amphibious twin-engine
Sikorsky S-38. The trip was to learn more about the carnauba palm tree (
Copernicia prunifera) of north eastern Brazil which produced
carnauba wax, one of the main products of his company, and to determine whether groves of these trees could produce enough to meet future demand. This led to investments in Brazil, establishment of a subsidiary in 1960, and eventually to the foundation of the
Serra das Almas Private Natural Heritage Reserve to protect an area of the
caatinga biome including wild carnauba palms. His 1935 two month, 7,500 mile journey to northeastern Brazil as well as his somewhat difficult relationship with his son,
Samuel Curtis Johnson Jr., was documented in his son's 2001 film ''Carnuba: A Son's Memoir''. The film includes footage from a repeat of that journey that the Johnson family undertook in 1998. == Personal life ==