Documents, Speeches, Audio, Video 

• 100 Milestone Documents
  "The following is a list of 100 milestone documents, compiled by the National Archives and Records Administration, and drawn primarily from its nationwide holdings. The documents chronicle United States history from 1776 to 1965."
• 250+ Killer Digital Libraries and Archives
  State-by-state list of historical archives in the US.
• American Memory: Historical Collections for the National Digital Library
  From the Library of Congress, millions of items organized into over a hundred historical collections.
• American Presidency Project
  Over 70,000 documents including speeches, addresses, proclamations, executive orders, chats, and press conferences given by U.S. Presidents.
• American Rhetoric
  This award-winning site includes text files, audio, video, and images in sections such as Online Speech Bank, Top 100 Speeches, Movie Speeches, Christian Rhetoric, Rhetoric of 9-11, Speech of the Week, and more.
• The Avalon Project at the Yale Law School
  "Documents in law, history, and diplomacy" browsable by name or searchable by keyword.
• CARRIE: A Full-Text Electronic Library
  Links to historical documents online. Includes European history,American history, and UN and international documents, among other collections.
• A Chronology of U.S. Historical Documents
  From the University of Oklahoma, U.S. historical documents arranged in chronological order, from pre-colonial days through the present.
• Collect Britain
  "Collect Britain presents 90,000 images and sounds from the British Library, chosen to evoke places in the UK and beyond." Includes maps, drawings, sheet music, bird songs, early wax cylinder recordings, and more.
• Cornell University Library Windows on the Past
  "The Cornell University Library Windows on the Past is a grouping of selected historical materials which have been digitally scanned and are available for on-line browsing and searching." Includes a Historic Math Book Collection, New York State Historical Literature, and International Women's Periodicals, among other offerings.
• DOUGLASS
  "Douglass is an electronic archive of American oratory and related documents. It is intended to serve general scholarship and courses in American rhetorical history at Northwestern University."
• EuroDocs
  "Online Sources for European History. Selected Transcriptions, Facsimiles and Translations."
• Footnote
  "People may fade away, but their stories live on.... Footnote puts millions of original documents never seen on the web before at your fingertips—and lets you share your discoveries with the world."
• Google: National Archives Videos
  Google is making more than a hundred archival videos from the National Archives available to the public.
• Historical Text Archive
  Large collection of historical documents from American and world history.
• History and Politics OutLoud
  "History and Politics Out Loud is a searchable archive of politically significant audio materials for scholars, teachers and students."
• HistoryLink101
  Photos, images, maps, and links for world history classes.
• TheHistoryNet: Where History Lives on the Web
  From About.com, extensive links to archival historical information on the web.
• In the First Person
  "Provides in-depth indexing of more than 2,500 collections of oral history in English from around the world."
• Internet History Sourcebooks Project
  "Collections of public domain and copy-permitted historical texts presented cleanly ... for educational use."  This extensive collection of documents and links is a great starting place for historical research of all sorts.
• Lifelines: Social Studies: Primary Documents
  Annotated listing of good sites for high school students to find online versions of primary source documents.
• National Archives and Record Administration: Exhibit Hall
  Text, historical information, and facsimile images of U.S. documents, treaties, and speeches. Also includes large collections of images of American people, places, and events.
• Old Pictures
  "An extensive collection of original, historical photographs. This collection includes a vast array of photographs spanning the years 1850 to 1940."
• Our Documents.gov
  "A list of 100 milestone documents, compiled by the National Archives and Records Administration, and drawn primarily from its nationwide holdings. The documents chronicle United States history from 1776 to 1965." (Note: Flash animation.)
• StoryCorps
  "StoryCorps is a national project to instruct and inspire people to record one another's stories in sound. ... we'll also add your interview to the StoryCorps Archive, housed at the American Folklife Center at the Library of Congress, which we hope will become nothing less than an oral history of America. "
• University of Michigan Documents Center
  "The Documents Center is a central reference and referral point for government information, whether local, state, federal, foreign or international. Its web pages are a reference and instructional tool for government, political science, statistical data, and news."
• U.S. News: Eyewitness to History
  "In the pages that follow are ... letters, transcripts, and diaries — from Americans famous and not — that revive crucial moments in history with an intensity and intimacy that no secondary source can match."
• World History Archives
  "Documents to support the study of world history from a working-class and non-Eurocentric perspective."

 Cartoons 

• Association of American Editorial Cartoonists
  Includes current cartoons, cartoons by topic, cartoons by cartoonist, lessons, news related to editorial cartoons, Cartoons for the Classroom, and more.
• British Cartoon Archive
  "A guide to the British Cartoon Archive's holdings of cartoon cuttings and original artwork. It contains more than 120,000 catalogued cartoons, mostly from the last hundred years."
• Cartoon America
  Exhibition of a hundred cartoons about the United States. From the Library of Congress.
• Cartoon Prints, American
  "This assemblage of more than 500 prints made in America during the eighteenth and nineteenth centuries encompasses several forms of political art."
• Daryl Cagle's Professional Cartoonists Index
  Wonderful collection of topical and political cartoons, with archives going back several years.
• The Editorial Cartoons of J.N. "Ding" Darling
  Collection from Pulitzer Prize winning cartoonist and conservationist from the first half of the 20th century.
• FDR Cartoon Archive
  Collection of political cartoons about President Franklin Roosevelt from 1932 to 1944.
• Five Decades of Herblock
  A collection of essays and cartoons from Washington Post political cartoonist Herb Block spanning the second half of the 20th century.
• It's No Laughing Matter
  "Analyzing political cartoons."
• The Learning Page: Political Cartoons
  Annotated list of political cartoon sites online for both students and teachers.
• Policial Cartoons.com
  "This is the biggest, searchable database of political cartoons, by the best editorial cartoonists in the world."