Geography

Worldatlas.com

Maps, Flags, Geography, and Clip-Art

A Teacher's Geographic Guide to the Holocaust

Historical Atlas of the 20th Century

Lesson Ideas

Social Studies Lesson Plans: Dr. Marty Levine

Library of Congress: Page for Teachers  

The New York Times Learning Network

Social Studies Sources - Dr. Fred Risinger

Edsitement - National Endowment for the Humanities

Searchable by topic and grade level.

PBS Teachers Resource

Lesson ideas tied to PBS films; good source for finding relevant films, too.  

100 Milestone Documents 

Major documents in U.S. History and ideas for working with them.

ReadingQuest.Org

Strategies for reading comprehension applied to social studies.

C-SPAN Classroom

Resources for civics and U.S. Government; includes many video clips. 

Organizations

H-High-S

Discussion list for social studies teachers

Missouri Council for the Social Studies

National Council for History Education

National Council for the Social Studies

Organization of American Historians

The Society for History Education

World History Association

Primary Source Sites

100 Milestone Documents

Major documents in U.S. History.

American Memory: Historical Collections for the National Digital Library

American Women's History: A Research Guide

EarthStation

Audio, video, and photos.

Historical Texts Project (Hanover College)

History.Com

The History Channel's archive of speeches and videos.

Internet Modern History Sourcebook

Divided by subject.

National Archives

Lessons based on primary source documents.

Many Pasts

About 1000 primary source documents related to the U.S. survey course.

Spartacus Educational

A variety of British and U.S. documents.