The Index of Patents provides a list of patents registered in a particular year, arranged by subject of invention and name of patentee. From 1842-1871, claims descriptions, and illustrations are also included.
Information is available at UCF in microfilm (1842-1973), paper (1927-1996) and electronic (1976+).
See also the U.S. Congressional Serial Set for the Annual Reports from the Commissioner of Patents which usually included a list of patents and patentees. The College of Wooster provides a finding list to identify which volumes of the Serial Set contain the Annual Reports, Commissioner of Patents.
American Memory (Library of Congress) "provides free and open access through the Internet to written and spoken words, sound recordings, still and moving images, prints, maps, and sheet music that document the American experience."
Does SSA make its Death Master File available online for the purposes of genealogical research? -- "Although the Death Master File is not available online from SSA, the United States Department of Commerce's National Technical Information Service (NTIS) offers a subscription service for online queries of the Death Master File through their website....Please note that other parties have purchased SSA's Death Master File Extract through NTIS and then posted it on their own websites. Although these private parties call/refer to their own websites as SSA's "death index" or SSA's Death Master File, these are not endorsed by SSA, nor can SSA confirm that these private websites are kept up-to-date or accurate with SSA's death data in any way."
RootsWeb's Guide to Tracing Family Trees: Social Security Death Index provides guidance on research using social security numbers.
Military Personnel Records -- "The National Personnel Records Center, Military Personnel Records (NPRC-MPR) is the repository of millions of military personnel, health, and medical records of discharged and deceased veterans of all services during the 20th century. (Records prior to WWI are in Washington, DC.)"