The test ban treaty negotiations had their origins in a larger-than-expected U.S. thermonuclear explosion in the Pacific in 1954. Nearly a decade later, in 1963, Great Britain, the Soviet Union, and the United States concluded a treaty that permitted underground explosions but banned them in other environments. It was the first treaty of the Cold War to place limits on nuclear operations, but it was not what the negotiators had originally sought – a complete ban on tests. A substantial amount of pre-negotiations on the limited test ban treaty occurred during the Eisenhower administration. The idea itself first surfaced very early in these pre-negotiations. The willingness of two U.S. presidents and a British prime minister to persevere in the face of domestic opposition and foreign difficulties shows the importance of individuals in the negotiating process. The effect on negotiations of world events not directly related to the talks is demonstrated by the impact of the Sino-Soviet split, the unsettled status of Berlin and Germany, and the Cuban Missile Crisis. Single-issue lobbyists, representing the interests of weapons laboratories and the views of those opposed to U.S.-Soviet cooperation, caused major difficulties during the years of negotiations, as reflected in the interagency bargaining that preceded policy decisions. This included the use of scientific information both to advance and to block the negotiations. As a leading member of the advisory and negotiating teams during much of the period discussed in this article, the author pays tribute to professionals in the Eisenhower and Kennedy administrations whose dedication and ingenuity kept the negotiations alive until circumstances finally crowned the effort with success.