This study explores the emergence of the sentence-final is all construction in American English. The construction stems from an amalgamation of sequenced sentences (or clauses), i.e. SENTENCE/CLAUSE + (and/but) that is all, giving rise to a type of anacoluthon, i.e. CLAUSE is all. Results of the survey tell us that the sentence- final is all construction begins life in the early twentieth century and demonstrates an upward trend towards the present. Theoretically, the specifiable linear sequence of sentences or clauses in particular pragmatic conditions, i.e. co-text (Halliday 2004), provides partial evidence for a cline of clause integration in grammaticalization: parataxis > hypotaxis > subordination (Hopper and Traugott 2003). This newly-born construction originating in American English is introduced to other varieties of English in the same way as some other innovations, such as be like and the bottom line is (that), have already been used worldwide.