Quick Facts, by the U.S. Census, gives quick overviews and comparisons of municipalities (cities, towns, and villages), counties, states, and the US as a whole.
It includes data on the population, demographics, housing, education, health, broad overviews of the economy and business, income and poverty, and transportation. Data can be returned as a table, map, chart, or dashboard.
The above link goes to Wisconsin data, and users can narrow it further by county or municipality. To access Quick Facts for the US as a whole, click here.