They didnt have guitars yet in 1775.
Actually, your 1775 date is about dead on for the first 6-string guitars. Pretty appropriate! The guitar had been developing for a long time though.
Some web trivia to help you when you're a Jeopardy contestant:
1265 Juan Gil of Zamora mentions the early guitar in "Ars Musica.
1283-1350 Guitarra Latina & Guitar Moresca are mentioned multiple times in the poems of the Archpriest of Hita
1306 A "gitarer" was played at the Feast of Westminster in England
1404 "Der mynnen regein" by Eberhard Von Cersne makes reference to a "quinterne."
1487 Johannes Tinctoris described the guitarra as being invented by the Catalans. This refers to the four course guitar. Each course represents one pair of double strings.
1546 "Tres Libros de Musica en Cifras para Vihuela" by Alonso Mudarra is the first publication to include music for guitar.
1551-1555 Nine books of tablature were published by Adrian Le Roy. These include the first pieces for 5 course guitar. The addition of the fifth course was attributed to Vicente Espinel
1600-1650 Many publications of tablature for the guitar. It's popularity begins to rival the lute.
1674 Publication of "Guitarre Royal" by F. Corbetta increased the guitar's popularity. It was dedicated to Louis XIV.
1770-1800 A sixth string was added to the guitar and the courses were replaced by single strings.