From their press release: The U.S. Census Bureau has released its most detailed look at America’s people, places and economy. New state and local statistics on income, poverty and health insurance are available in briefs, detailed tables, data profiles and more. The American Community Survey (ACS) also produces statistics for more than 40 other topics.
Curious about county-level data? This link will take you to the most up-to-date table for indicators by Illinois county (2018 1-Year Estimates).