What Happened on April 9th
The contract is signed between the University of Pennsylvania’s Moore School of Electrical Engineering and the US Army to build the Electronic Numerical Integrator and Computer (ENIAC), a machine capable of the then-remarkable speed of 5,000 additions per second. ENIAC was shrouded in wartime secrecy since its main purpose was to compute "firing tables" for artillery shells. Before ENIAC, this was done by women (called "computers") working in large groups and using mechanical desktop calculators. ENIAC was not completed until after the war (February 1946) but a generation of computer designers learned from its design and from the summer course given by Eckert and Mauchly at the Moore School between July and August of that same year. ENIAC could solve a wide range of general purpose computing problems and was also used for classified military projects, including preliminary calculations for the US hydrogen bomb.