https://www.americanrhetoric.com/speechbank.htm
An index of 5000+ full text, audio and video (streaming) versions of public speeches, sermons, legal proceedings, lectures, debates, interviews, other recorded media events, and a declaration or two" (site description). Index links alphabetized by first name. Available mediums flagged with [T] (text), [A] (audio), [V] (video).
https://www.c-span.org/quick-guide/
The video archive includes all programming from the three C-SPAN's networks. Coverage spans Congressional sessions from 1987-present with special indexing by person with full text transcripts.
Index to American Women Speakers, 1828-1978
Main Library Reference PS 400 .M35
Indexes by author, subject, and title the speeches of women appearing in more than 200 publications, including collected works. This work was updated with We Shall Be Heard: And Index to Speeches by American Women, 1978 to 1985 (Main Library Reference PS 408 .M37 1988).
Representative American Speeches (1957/58-1992/93)
Main Library General Collection PS 668 .B3
A compilation for a given year of the "most notable" speeches from politics, business, and academe.
Speech Index: An Index to 259 Collections of World Famous Orations and Speeches for Various Occasions
Main Library General Collection AI 3 .S85 1966
Speech Index: An Index to 259 Collections of World Famous Orations and Speeches for Various Occasions. Fourth Edition Supplement, 1966-1980.
Main Library General Collection AI 3 .S85 1966-1980
A dictionary catalog with entries for each speech under author, subject, and type of speech.
Full texts of speeches on a wide range of political and policy topics.