Research in Military Records: Vietnam War.Research in Military Records: Vietnam War. This site is the National Archives portal to their records on the Vietnam War. Most of the records relate to casualty counts, available for both the United States and Vietnamese. U.S. casualty counts are further broken down by state, year, branch of service, and other pertinent factors. Files on prisoners of war and soldiers missing in action can also be searched and downloaded in PDF form. When searching, however, users are kicked over to the National Archive’s Access to Archival Databases website, where they must redo their search from scratch.