It is so easy: from a browser alone you can begin to think how to use the tools before even starting them (and no "learning the program" period, because you already know the language that they operate in). The search engine does it for you by a cool added algorithm that shows the timeline of your search.
For instance, type in "transportation".
One of the search results is going to show you the timeline of references to the word.
It starts with the beginning of eighteenth century.
Next, you can choose time slices.
For instance, choose 1700-1750 to see all the available documents from the period.
You can then go through the time-slices (even by years) individually and weave a story that can from there be analyzed in context.
Later bring your own set of data into tools.
The only obstacle right now to infinite possibilities for deeper analysis and more sophisticated queries are the percentages of the publishers' (but not necessarily owners') claimed values of those archives, books, newspapers scanned and transcribed and made into a database.