Over 230,000 Americans have served as Peace Corps volunteers since the agency was established in the early days of the Kennedy administration. Nisley, a former volunteer in the Dominican Republic, argues that the Peace Corps, which costs roughly $50,000 per volunteer per year, has provided a cost-effective way to advance U.S. foreign policy. Small project by small project, the volunteers promote development in poor countries. Statistical evidence suggests that their sustained interactions with local citizens improve perceptions of the United States. In perhaps its most important role, the Peace Corps serves as a graduate school in foreign policy, preparing volunteers for careers in diplomacy and international development. The White House’s enthusiasm for the Peace Corps has waxed and waned, Nisley finds, depending on presidential preferences and perceived security threats. For John F. Kennedy, the Peace Corps aligned well with his Alliance for Progress initiative, which aimed to promote democracy and economic growth in Latin America. Richard Nixon saw the Peace Corps as a haven for those opposed to the Vietnam War and reduced the number of volunteers. Later, Ronald Reagan expanded the agency’s presence in Central America to counter leftist insurgencies.