(Image is The Bill of Rights, from the National Archives. Image is hyperlinked to National Archives catalog record.)
Governments produce a wide array of documents ranging from Congressional or Parliamentary debates and reports, census data, agency or departmental papers to brochures, maps and posters. As primary sources these official governmental publications provide insight into all aspects of history from social issues to politics, from cultural mores to scientific endeavor.
Many free, specialized databases with digitized government documents can be found on the Internet. Check out these library-recommended government document sites: