Cryptologic History

"On This Date in Cryptologic History" Calendar

1947: Grace Hopper & the First Computer "Bug"

Wednesday, September 9, 2026

Always ready to pioneer new methods of problem-solving, Captain (at the time) Grace M. Hopper made history on September 9, 1947, by removing the first computer bug. It was a moth that got into the relay calculator and was the first actual case of a bug being found.

Afterward, the operators coined the phrase that they have “debugged the computer.” Of course anyone with a computer science background probably knows that story. (Shared by U.S. Navy Cryptology and Technology)

Learn much more about USN Rear Admiral Grace Hopper via the link below.

Learn About the Pioneers

Learn about the various individuals and groups who paved the way in the field of cryptology, cyber, computers, and more.