Census maps of population: Population over Time and Distribution of slaves in 1860.
Through the Decades section: This section includes lesson plans, maps, classroom resources, and games.
Fast Facts give paint a picture of the United States both statistically and culturally.
Great reference tool Barb! I like the "Through the Decades" Fast Facts section, this would be a great extension activity for kids that are history buffs and like to collect this kind of detail.
United States Historical Census Data Browser to find
raw data for projects. You may search census data by decade
from 1790 to 1970. There is a wealth of information here.