Profile America: Rocky Mountain Locusts Swarm

Friday, July 20th. On this date in 1874, the largest swarm of Rocky Mountain Locusts ever recorded blackened the skies from the Dakotas to Texas, and feasted on America’s farms.

Like an Old Testament plague, the moving swarm was estimated to cover almost 200,000 square miles. A calculated 12.5 trillion locusts ate not only crops, but also leather, paint, clothing and the wool off of living sheep. The plague ended on July 30th, and subsequent swarms were much smaller. In fact, the last living Rocky Mountain locust was noted in 1902.

Such a phenomenon today would still be overwhelming, but some 104,000 Americans work in nearly 14,000 extermination and pest control establishments to combat smaller infestations.

Profile America is in its 22nd year as a public service of the U.S. Census Bureau.

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