Illinois adopted its individual income tax in 1969—more than 50 years after the federal government started to tax wages and 30 years after the typical state.
See when each state adopted its individual income tax in this interactive map:
According to the Tax Foundation, which assembled the data, the 1930s saw the greatest adoption of the individual income tax as a stopgap against the drop in property tax revenue during the Great Depression.
Only three states—Hawaii, Wisconsin, and Mississippi—adopted an individual income tax before the federal government. Seven states today still do not have an individual income tax.