'americanism' originates from 'American', specifically the word 'American', where 'America' referred to the continent and '-ism' denoted a distinctive practice or ideology.

'American' changed from 'Amerigo Vespucci', the Italian explorer's name, and eventually became the modern English word 'American'.

Initially, it meant 'pertaining to America', but over time it evolved into its current meaning of 'a characteristic feature of American English or culture'.