Includes full text of 180 Presidential speeches from Washington to Reagan. Do a keyword search under speeches . General collections of speeches shelve in the PN6129 and PS660-PS669 sections of the book stacks. Edited by D.J. Brewer. Edited by O. Peterson.
Some periodicals contain primarily speeches.
Indexed in Readers Guide. Weekly Compilation of Presidential Documents. They can be a rich source of information on speeches. A phrase search on famous speeches is a good way to start.