The United States began its postwar atomic weapons testing program in 1946. Over the following 16 years, hundreds of thousands of troops were subjected to radiation in various experiments, according to this report. Here are some of their stories.

“The guys started saying we were guinea pigs. Atomic guinea pigs,” recount veterans of Operation Crossroads, a project designed to “show how warships would hold up to a nuclear blast” but also involved soldiers and living animals.

This was the very same operation that turned Bikini Atoll in the Marshal Islands into a radioactive wasteland.

“They made us sign, saying ‘don’t tell anyone or you can be tried or treason,’” veteran Frank Farmer told the NYT.

Between weapons testing, fallout cleanup and further experiments continuing through the Cold War, an astounding number of American citizens were exposed to harmful radiation with no knowledge of its injurious effects.

An internal investigation by the Clinton administration resulted in compensation issued to some veterans and even a formal apology from President Clinton himself. Unfortunately it appears that there are still quite a few soldiers that have gone unrecognized for their enduring sacrifice.

Of course we have all our veterans to be thankful for, but this brief historical examination in the New York Times’ “Retro Report” series shines a light on a group of people that seem to have been sidelined in history.