After the end of World War II, top-secret research continued across the United States as engineers and programmers rushed to complete their confidential assignments. Among them were six pioneering women, tasked with figuring out how to program the world's first general-purpose, programmable, all-electronic computer - a machine built to calculate a single ballistic trajectory in twenty seconds rather than forty hours by human hand - even though there were no instruction codes or programming languages in existence. But their story, never told to the reporters and scientists who thronged the huge computer after it became public, was lost. Kathy Kleiman, through meticulous research and vivid prose, brings these women back to life, and back into the historical record. For more than two decades, she met with four of the original six ENIAC Programmers, poured over documentation and images, and recorded extensive oral histories with the women about their work. She found stories that had been relegated and dismissed by even computer history experts, who had assumed the women in the old black-and-white pictures with ENIAC were nothing more than models.