The research discusses the history of both British English and American English. The main goal is to find how far the history of American English is originated in British English. The research also sheds light on the historical factors beyond the linguistic differences between British English and American English. However, these differences are restricted to vocabulary and spelling in order to give them more depth in analysis. The study comes up with several interesting findings. Among these findings is the fact that American English is basically an outcome of Elizabethan English which the English settlers brought with them as they came to the North American Continent in the sixteenth century. Nevertheless, despite the fact that the main effect on American English resulted from British English on that time, there were many other resources that impacted it throughout time, such as American Indian Pidgin English, French, and Spanish and recent immigration of other various peoples like the Italian, Chinese and German to the United States. Moreover, with the passage of time, American English influenced British English and enriched its vocabulary, especially in the case of "Americanism."