“Who invented the computer? For anyone who has made a pilgrimage to the University of Pennsylvania and seen the shrine to the ENIAC, the answer may seem obvious: John Mauchly and J. Presper Eckert Jr., who led Penn’s engineering team in the 1940s. As it says on the plaque, the giant machine made of 17,468 vacuum tubes was the “first electronic large-scale, general-purpose digital computer.” But notice all the qualifying adjectives. Does this mean there was a smaller digital computer that actually came first?

Yes, it does. And that computer was invented by John Vincent Atanasoff, who, with his partner Clifford Berry, started assembling the machine in the basement of the physics building at Iowa State University in the late 1930s.”

Pulitzer Prize-Winning Novelist Tells the Tale of the World’s First Computer (wired.com)