Number of counties, land area, and population for the 50 states plus the District of Columbia
statepps
Date frame with the following 7 variables:
state name
number of counties in state
cumulative number of counties
land area of state, 1990 (square miles)
cumulative land area
population of state, 1992
cumulative population
Lohr (1999). Sampling: Design and Analysis, Duxbury, p. TODO and 445.