I have always been fascinated by phrases, words and their etymology. As I result, I find a utility from google very interesting to allow students to evaluate the usage of a word within the context of history. Google has created a site called the Ngram Viewer. It allows a user to search all books scanned by google for the usage of a word over time. For example, I thought it would be interesting to see the words of freedom and liberty. These are two words that are used frequently today.
Using this tool you can obviously see the importance of these words leading up to and during the American revolution. If we move to the modern era 1800 and beyond we can see the impact of these words today.