Remarkable shifts in the demographic behavior of Americans have occurred over the past two decades. In this process, immigration interacts with fertility and mortality rates to determine the size and composition of the population. Peaceful Invasions outlines arguments for an immigration policy that will not lead to an ever-growing United States population and which will ease the process of cultural adjustment for newcomers. Such an immigration policy is called 'liberal limitationist' because one reason for advocating less immigration is to protect United States workers and steer the United States economy toward a high productivity trajectory so there is more income to share with the poor. Co-published with the Center for Immigration Studies.