The key-note and countersign of life in these cities [of the U.S. West] is the word "hustle." We have caught it in the East. but we use it humorously, just as we once used the Southern word "skedaddle," but out West the word hustle is not only a serious term, it is the most serious in the language. [Julian Ralph, "Our Great West," N.Y., 1893]Sense of "to get in a quick, illegal manner" is 1840 in American English; that of "to sell goods aggressively" is 1887.