Between October 22 and November 29, 1951, the United States government conducted nuclear-weapon tests at the Nevada Proving Ground (later called the Nevada Test Site). About 6,500 American soldiers were required to participate in the non-voluntary mission.
The official report of the testing, prepared by the U.S. Department of Defense (and released in PDF format), provides details:
This report describes the activities of DOD military and civilian personnel in Operation BUSTER-JANGLE, the second series of atmospheric nuclear weapons tests conducted at the Nevada Proving Ground from 22 October through 29 November 1951.
The BUSTER-JANGLE series consisted of seven events. DOD personnel participated in Exercises Desert Rock I, II, III and in scientific projects conducted by the test units. Radiological safety criteria and procedures were established and implemented during Operation BUSTER-JANGLE to minimize participants' exposure to ionizing radiation. (See page 3, Section 20 - Abstract, of the Report.)
This video clip, digitized and placed online by the National Archives, depicts troops observing "DOG Shot." The official report notes the following about Shot DOG:
Shot DOG, an airdropped nuclear device, was detonated with a yield of 21 kilotons at 0730 hours on 1 November 1951. The shot was fired 1,417 feet above the terrain of Area 7, Yucca Flat.
As Part of Exercise Desert Rock I, the armed services fielded a troop observer program with 2,796 participants, a tactical troop maneuver with 883 participants, and damage effects tests with 60 participants. All troops observed the shot from a location 11 kilometers south of ground zero.
The men participating in DOG Shot were based at Camp Campbell, Kentucky and Fort Lewis, Washington.
Video clip of Buster-Jangle Dog Shot - which took place on November 1, 1951 - online, courtesy U.S. National Archives.
Quoted passages from the official report, prepared and released by the U.S. Department of Defense, as noted above.