The History of U.S. Military Deaths

The Congressional Research Service is the neutral research arm for the Congress. It publishes detailed and concise reports on a variety of topics, and has just released a new edition of a report on deaths in the U.S. military from the Revolutionary War and the War of 1812 to the present. The new report, American War and Military Operations Casualties: Lists and Statistics has been updated to include Operation Iraqi Freedom.
According the the CRS:

“This report is written in response to numerous requests for war casualty statistics and lists of war dead. It provides tables, compiled by sources at the Department of Defense (DOD), indicating the number of casualties among American military personnel serving in principal wars and combat actions.”

Beginning with the Korean War, the report provides information on specific cause of death and demographic data.
UC Hastings subscribes to the Congressional Research Service, or you can access the report from Secrecy News.