Close any open views or tables. Then open the Attribute Data Demo view from the Project Window. The most prominent theme in this new view is the census tracts for Sonoma County. The US Census Bureau takes a national census every 10 years. Data from the censuses are available for many area breakdowns, such as state, county and city level.
Smaller areas are available too.
One of the most commonly used is the census tract. A tract averages 4000 persons, though it can range from about 2000 to 10,000. For all these units, a huge amount of data is available on population, ethnicity, income, education, and housing. We will use the tracts here to examine some characteristics of Sonoma County. To add some identifying information for the county, I have also added major roads and cities, and labeled some cities.