USA HISTORY

Detailed explanation-1: -With industrialization, improvements in medical knowledge and public health, together with a more regular food supply, bring about a drastic reduction in the death rate but no corresponding decline in the birth rate. The result is a population explosion, as experienced in 19th-century Europe.

Detailed explanation-2: -Immigration describes individuals moving into the population while emigration describes individuals exiting the population. If immigration rates are higher than emigration rates, the population increases, whereas if emigration rates are higher than immigration rates, the population size decreases.

Detailed explanation-3: -Between 1750 and 1800, the populations of major countries increased between 50 and 100 percent, chiefly as a result of the use of new food crops (such as the potato) and…

Detailed explanation-4: -The rate of population growth is the rate of natural increase combined with the effects of migration. Thus a high rate of natural increase can be offset by a large net out-migration, and a low rate of natural increase can be countered by a high level of net in-migration.