Friend, there are many, many, many people of Polish descent and Polish origin in Chicago.
Polish folks are one of the largest European-American ethnic groups in Chicago (see the Wikipedia entry on Poles in Chicago for some confusing information about exactly how many Polish people there are in the city.)
Polish people live everywhere in Chicago - there isn't a particular neighborhood or area where this population lives.
Finally, those who grow up in Chicago will be happy to tell you about how they got Casimir Pulaski Day off from school.