Final answer:
Population changes in the states are due to changes in demographics and social factors, immigration policies, birth rates, and migration patterns, including the impacts of urbanization, healthcare, birth control, and economic circumstances.
Step-by-step explanation:
The number of people in a house or population in state changes over time due to a variety of factors. These include changes in population and demographics, changes in immigration policies, and changes in birth rates. Population composition is influenced by social trends, such as the delay of childbirth, economic circumstances like the cost of living in urban areas, and external factors like epidemics. Demographic characteristics like birth and death rates, life expectancy, and net immigration, which represent the change in population due to people moving in or out of a country, also play a crucial role.
Historically, the U.S. population has experienced growth and decline, with shifts from rural to urban living, changing family sizes, healthcare improvements, and the use of birth control all contributing to population changes. The demographic study, or demography, includes the analysis of fertility, mortality, and migration to understand these dynamics. Migration, both immigration and emigration, additionally impacts population size and composition, as individuals move either voluntarily or involuntarily, due to various personal and political reasons.