The U.S. Army's Alsos Mission in World War II

As work on an atomic bomb progressed in the United States, it was reasonable to assume that there had been corresponding progress in Germany. Thus, the U. S. Army initiated the Alsos Mission in the fall of 1943 as part of the Manhattan Project.

The objective of the mission was to follow immediately in the wake of our armies in the invasion of Europe, for the purpose of determining precisely how much the Germans knew about the atomic bomb and how far they had progressed in its construction.

The original mission (Alsos I) went to Italy in December 1943, but gained little information of interest, due in part to the slow progress of the Allied advance on Rome.

The second mission (Alsos II) followed the Allied advance from France to Germany in 1944 and 1945. Ultimately it consisted of seven military officers and thirty-three scientists.

Interrogation of French and German scientists combined with the investigation of laboratories confirmed that the German program was never close to producing an atomic bomb. The mission also tracked down and secured large amounts of uranium materials in France, Belgium, and Germany.