By the early 19th century in the United States, the gesture was affiliated with the letters "O" (formed by the circle) and "K" (derived from the extended fingers). While it is not known exactly how the OK gesture and the corresponding verbal expression coalesced, the English professor Allen Walker Read dates the expression's rise in usage to an 1839 humor piece in the "Boston Morning Post" describing the expression "o.k." as meaning "all correct", suggesting comically misspelled initials, at a time when acronyms for misspelled words were in vogue. Several other broadsheets in Boston, New York and Philadelphia ran with the expression in their own columns, some with misspellings of "all correct" such as "oll korrect", bringing the phrase into the vernacular of American English.