Abstract. This paper investigates the historical foundations of American English through a qualitative historical-linguistic analysis. It explores the linguistic evolution resulting from early British colonization, contact with indigenous and immigrant languages, geographic isolation, and socio-cultural factors. Emphasis is placed on the roles of dialectal variation, lexical innovation, and standardization efforts, particularly those of Noah Webster. The findings highlight how American English emerged as a distinct variety shaped by internal diversification and external influences. Furthermore, the global impact of American English in the 20th century underscores its significance in international communication and linguistic dominance. Understanding these historical dynamics offers deeper insight into the current form and function of American English.