Nearly two-thirds of Americans live in incorporated places, commonly referred to as cities. As the majority of the nation’s population lives in cities, patterns of population change among cities and the social and economic conditions affecting them often represent national trends. Using data from the 2000 and 2010 censuses and 2013 population estimates, this report examines the population in cities and highlights how city populations changed between 2000 and 2010, and between 2010 and 2013. The report discusses the distribution of the population in cities by region, state, and city population size. It also highlights the fastest-growing cities, city population densities, annexation, and new incorporations between 2010 and 2013.