1930s as greater numbers of black families moved in, but this process dramatically
accelerated after World War II. Several factors contributed to the movement of
whites to the suburbs. The construction of the interstate highway system in the
1950s allowed whites in the suburbs to live a considerable distance from the inner
city, but still commute there on a daily basis relatively easily. Low land values in
the countryside, relatively low mortgage rates, and the application of mass produc-
tion techniques to housing construction after the war enabled many whites to pur-
chase homes in the suburbs, but blacks were unable to follow because incomes in
the black communities were lower, and few blacks could afford to relocate. More-
over, discriminatory practices in lending prevented blacks from purchasing property
in predominantly white areas. “Redlining,” for example, was a tactic mortgage lend-
ers used to maintain the segregated character of housing in the large cities. When a
residential area was redlined, mortgage lenders would deny mortgage applications
of blacks and other minorities for property within the area, effectively prohibiting
them from living in that part of the city. This was done primarily to protect property
values, because the mortgage holders felt that the presence of minority residents
would depress the value of existing residences. Such discriminatory practices are
now illegal, but their effect remains, as most urban areas in the United States remain
quite segregated. However, the U.S. Bureau of the Census has declared in recent
census reports that the level of segregation in American cities is declining, as white
neighborhoods have gradually become more integrated.Sequent Occupance
The American geographer Derwent Whittlesey is credited with first articulating
the concept of sequent occupance, although he drew heavily on the theoretical
work of others in the field of cultural geography, especially the ideas of Carl Sauer
(see sidebar). Sequent occupance is the notion thatlandscapesare shaped over
time by the sequential settlement, or at least sequential use, of that landscape by
various groups who occupy the land. Thus, according to the proponents of this
approach to landscape study, a place can be understood only through an examina-
tion of the historical impact of such occupation, and a comprehension of the nature
of the culture at each stage of occupation. The theory had a deep influence on the
approach of historical and cultural geographers in the United States in the 1920s
and 1930s. The concept of sequent occupance has its roots in Social Darwinism,
in that the landscape is seen as evolving over time due to the various influences
upon it, and the condition of the present landscape contains elements from all306 Sequent Occupance