Hint: When searching in a database always start with the advanced search and see if you can filter (or limit) by document type. If they include "speech" as a type, choose that and then add your keywords to the search boxes. Tip: some of the more general databases like Academic Search Premier will allow you limit and then search without any keywords. This is a great way to browse for a speech if you don't have anyone in particular in mind.
Hint: For older speeches you may have to use a print index, there are several listed below specifically for speeches.
Hint: The more famous the speech, the more likely you will be able to find it through a Google search. Just make sure you evaluate the site the speech comes from — there are several good sites listed below.