Weldon Spring is a city in St. Charles County, Missouri, United States.

[4] A post office called Weldon Spring was established in 1875, and remained in operation until 1957.

[5] In 1941, the United States Army purchased 17,000 acres of land in the surrounding area.

The Weldon Spring Ordnance Works built the largest explosives factory in the United States on the site.

[6] It was built to produce TNT and DNT for Allied forces during World War II.

A proposal appeared in 1945 suggesting the placement of United Nations Headquarters in the area.

[8] In 1955, the United States Atomic Energy Commission built a uranium ore processing plant on the 2,000 remaining acres.

20.1% of all households were made up of individuals, and 11.9% had someone living alone who was 65 years of age or older.

20.5% of all households were made up of individuals, and 13.3% had someone living alone who was 65 years of age or older.