Geographical mobility has long been one of the predominant factors in American life. This report highlights some of the important changes that have occurred in recent years, including changes in the volume and rates of movement, changes in the types of movement, differences in the characteristics of movers compared with nonmovers, and changes in the patterns of population distribution attributable to residential migration. These changes are important to federal, state, and local governments as they plan for needed services and facilities such as schools and hospitals. These data are also used by private industry to plan expansion and location of businesses and other services.