in 1942, after the us had entered world war ii and was faced with the problem of nazi german u-boat attacks on transatlantic shipping, philip m. morse was tasked with organizing a scientific group in the us navy to analyze anti-submarine warfare tactics. kimball was one of the first persons recruited by morse, and within the year he became morse's deputy director. during the war, the group was called the operations research group (org), and was later known as the operations evaluation group, us navy, and had grown to number some seventy analysts when the war ended in 1945. the org's work has become known as the pioneering application of or in the us, after or originated in the united kingdom a few years earlier through pioneering efforts by patrick blackett and other scientists. during the war, there was liaison between us and uk analysts in service of raf coastal command.