The term "tourist" dates to 1776, according to the Oxford English Dictionary. It didn't take long for it to become an insult. Here's the English diarist Francis Kilvert, writing c. 1870:
What was our horror on entering the enclosure to see two tourists with staves and shoulder belts all complete postured among the ruins in an attitude of admiration, one of them of course discoursing learnedly to his gaping companion and pointing out objects of interest with his stick. If there is one thing more hateful than another it is being told what to admire and having objects pointed out to one with a stick. Of all noxious animals, too, the most noxious is a tourist. And of all tourists the most vulgar, illbred, offensive and loathsome is the British tourist.