I have seen examples of the long S being used in old documents,for example in a picture of a medieval document about Muskets in which the word Musket was written as Muſket.
It appears to have been used in printing till the middle of the 19th century:
The long, medial, or descending s (ſ) is a form of the minuscule letter s, which was formerly used if s occurred in the middle or at the beginning of a word ("ſinfulneſs" for "sinfulness" and "ſucceſsful/ſucceſſful" for "successful"). The modern letterform was called the terminal, round, or short s.
In general, the long s fell out of use in Roman and italic typefaces in professional printing well before the middle of the 19th century. It "rarely appears in good quality London printing after 1800, though it lingers provincially until 1824, and is found in handwriting into the second half of the nineteenth century" as well as in printed collections of sermons. Woodhouse's "The Principles of Analytical Calculation", published by the Cambridge University Press in 1803 uses the long 's' throughout Latin-alphabet text. Abandonment by printers and typefounders
- The long s disappeared from new typefaces rapidly in the mid-1790s, and most printers who could afford to do so had discarded older typefaces by the early 19th century. Pioneer of type design John Bell (1746–1831), who started the British Letter Foundry in 1788, commissioned the William Caslon Company to produce a new modern typeface for him and is often "credited with the demise of the long s."