The Cambridge History of English and American Literature in 18 Volumes (1907–21).
VOLUME XVIII. Later National Literature, Part III.

XXX. The English Language in America

§ 5. Developments

But it is not chiefly here that we are to look for the causes of such differences as gradually separated American and British speech. New conditions of life, to be sure, called for new words: wigwam, tomahawk, squaw, papoose, prairie, canyon, and all the others that have become a part of the general stock of English. Stores in the Western world (the usage is not confined to the United States) really were stores and not shops. Our most common corn was maize, and it naturally became corn par excellence. Fall (autumn) and rare (underdone) are “Americanisms” only in the sense that they have retained a vitality here which even in England they have not wholly lost. Political life, sport, changed economic conditions, have all furnished the language with new words, or old words in new senses. The most striking differences, however, have come about, not through the retention of dialect words or the introduction of new words for new ideas, but because American English, in its comparative isolation, has not followed step by step the many changes that have occurred in British English since the seventeenth century.