To find national standards for all subjects , including civics, economics, geography, and history (but not social studies), using a single website, see the following website from McREL: http://www.mcrel.org/compendium/browse.asp
Social Studies: Social Studies Standards, which were developed by the National Council for the Social Studies: http://www.ncss.org/standards/toc.html
Following are websites for each of the specific social studies-related standards:
Civics: National Civics Standards developed by the Center for Civic Education: http://www.mcrel.org/compendium/Standard.asp?SubjectID=14
Economics: National Economics Standards developed by the National Council on Economic Education: http://www.economicsamerica.org/standards/index.html and http://www.economicsamerica.org/standards/standards.pdf
For a critique of the economics standards based on religious education lines, see this web site: http://www.edweek.org/ew/vol-18/08nord.h18
Geography: National Geography Standards, which were developed by the Geography Education Standards Project on behalf of the American Geographical Society, the National Council for Geographic Education, the Association of American Geographers, and the National Geographic Society: http://www.nationalgeographic.com/xpeditions/standards/matrix.html .
The standards may also be found on the Missouri Geographic Alliance website: http://www.umsl.edu/~mga/stand.htm
For activities related to the geography standards, see this National Geographic website: http://www.nationalgeographic.com/xpeditions/activities/matrix.html
History: National History Standards, which were developed by the National Center for History in the Schools: http://www.sscnet.ucla.edu/nchs/standards/
Psychology: National Standards for the Teaching of Psychology were developed by the American Psychological Association. These are standards that may be used by high school teachers who teach courses in psychology: http://www.apa.org/ed/hscontents.html