Manhattan Project got uranium from a Belgian's pre-shipped stockpile

In 1942 the US Army's atomic bomb program faced a raw-material problem more basic than any physics question: almost no high-grade uranium ore was known to exist inside American control, and prospecting or negotiating new mining rights from a standing start would take years the war didn't allow. Uranium from the Belgian Congo's Shinkolobwe mine was far richer than any other known deposit, but Belgium itself had fallen to Nazi occupation in 1940, and its Congo mining assets were now controlled from exile, making a US approach to acquire that ore politically and logistically uncertain.

When Colonel Kenneth Nichols was ordered by General Leslie Groves to secure uranium supplies, the standard path was slow: identify a deposit, negotiate mining and export rights with a government, arrange shipping through a war zone, and wait. None of that matched the timeline the Manhattan Project was operating on.

Nichols found the ore already shipped to Staten Island by Sengier, who had moved it to keep it from the Nazis, so sourcing collapsed into a contract.

Sengier shipped ore to New York in 1940 to keep it from Nazis, not for the US.

The ore sat in a Staten Island warehouse, already on US soil and accessible.

Nichols found Sengier in 1942 and the ore was immediately available, collapsing the sourcing timeline.

The pre-positioned stockpile eliminated the need for new mining, shipping, and negotiations.

When you need a scarce resource fast, check if someone already moved it to safety for their own reasons—their defensive hoard can become your supply.

The 1942 deal gave the US two-thirds of the uranium used in the Manhattan Project, solving a bottleneck that should have taken years. Sengier became the first non-American civilian awarded the US Medal for Merit, in 1946, and the Manhattan Project's own postwar histories credit his 1940 pre-positioning of the ore as removing what would otherwise have been the program's single hardest supply-chain problem.