And look what happened in Avebury
So it’s not just Stonehenge that people were writing about in the 1870s, but other linked stuff as well, such as Avebury and barrows – as The Englishman suggested. Here is the Ngram for those three words. As well as emphasising the peak in the 1870s, the Atkinson/Hawkins effect on Stonehenge in the 60s is highlighted (not present in barrow or Avebury), and we can see different patterns for Avebury in the 20th century: interest rising in the first decade (curiously, just BEFORE Gray’s major excavations, which were finally published in 1935), seemingly oblivious to Keiller’s work there in the 1930s, and rising again in the 1990s largely before the next major excavation programme that began in 1997 and was published in 2008. You could get quite ambitious with this, carefully selecting large numbers of words.