Google Ngram Viewer for a different way of looking language, culture, and history. The Ngram Viewer searches the texts of the hundreds of thousands of books scanned by Google Books for uses of terms from 1800 through 2000 and graphs the use onto a chart. You can search multiple terms (words or phrases to compare use over time; try, for example, Santa Claus, Saint Nicholas, and Father Christmas.
Note that search terms are case-sensitive.
You can also use Ngrams to delve into the Google Books collection. Below the graph, you'll find linked date ranges related to each search term. Click on any of these to see the books illustrating usage.