South Knox Bubba, in the post linked below, questions whether people had even heard of the f-word at the time of Deadwood (1876). Indeed they had, as the American Heritage Dictionary tells us.
The obscenity fuck is a very old word and has been considered shocking from the first, though it is seen in print much more often now than in the past. Its first known occurrence, in code because of its unacceptability, is in a poem composed in a mixture of Latin and English sometime before 1500. The poem, which satirizes the Carmelite friars of Cambridge, England, takes its title, “Flen flyys,” from the first words of its opening line, “Flen, flyys, and freris,” that is, “fleas, flies, and friars.” The line that contains fuck reads “Non sunt in coeli, quia gxddbov xxkxzt pg ifmk.” The Latin words “Non sunt in coeli, quia,” mean “they [the friars] are not in heaven, since.” The code “gxddbov xxkxzt pg ifmk” is easily broken by simply substituting the preceding letter in the alphabet, keeping in mind differences in the alphabet and in spelling between then and now: i was then used for both i and j; v was used for both u and v; and vv was used for w. This yields “fvccant [a fake Latin form] vvivys of heli.” The whole thus reads in translation: “They are not in heaven because they fuck wives of Ely [a town near Cambridge].”
Personal aside: NewMexiKen attended a high school run by the Carmelite Fathers. Knowledge of this poem then would have been both lucrative and dangerous.