The ENIAC was Eckert and Mauchly’s project. Eckert, with his brittle and occasionally irascible personality, was “the consummate engineer,” while Mauchly, always quiet, academic, and laid back, was “the visionary.” The physical construction of the ENIAC was undoubtedly Eckert’s achievement. He showed extraordinary confidence for a young engineer in his mid-twenties:

“Eckert’s standards were the highest, his energies almost limitless, his ingenuity remarkable, and his intelligence extraordinary. From start to finish it was he who gave the project its integrity and ensured its success. This is of course not to say that the ENIAC development was a one-man show. It was most clearly not. But it was Eckert’s omnipresence that drove everything forward at whatever cost to humans including himself.”

Martin Campbell-Kelly, William Aspray, Nathan Ensmenger, Jeffrey R. Yost, Computer: A History of the Information Machine