You can graph the trends for a single word or compare different words. For example, the following diagram compares the frequency of the terms "chess" and "baseball" between 1800 and 2008:
It shows that references to chess have remained fairly steady, while references to baseball climbed dramatically around 1880-1920, held steady until 1970, took off again until just past 2000, and then declined in the last few years.
Here is another example, comparing references to "checkmate" and "touchdown":
I also ran some searches involving the names of chess world champions, realizing that I would have to avoid champions with common names, because they would produce too many "hits" that were actually references to somebody else.