Human Geography: Evolution of United States County Boundaries
(1650, 1700, 1750, and census years from 1790 onward).
Human Geography: Population Pyramid
United States from 1950-2050 (in millions).
Physical Geography: Analemma (file download)
An analemma is a figure-8 curve that marks the position of the Sun at the same time each day throughout planet Earth's year. These photos were taken over a course of a year in New Jersey.