we can't see your return.
in most cases a part-year resident is not eligible to take credit for taxes paid to other states unless that income is taxed by both states. in addition, certain states have reciprocal agreements with other states so the income is taxed in only one state - generally the resident state. no tax credit is allowed.
here's a link to the Illinois instructions for the credit tax form - check to see if you qualify
https://www2.illinois.gov/rev/forms/incometax/Documents/currentyear/individual/IL-1040-Schedule-CR-I...
