This is fun:
http://chir.ag/phernalia/preztags/
You can find a range of presidential speeches going back to 1776, with their main words tagged and gathered into clouds that show how much they were used in that speech and the extent to which that term is new or old relative to earlier speeches. Unfortunately you can't search through the individual words across speeches, but hey, it's free. Check it out. Thanks to Elizabeth Stiles Knight of the library for sending this to me.
