1837: Chicago is incorporated as a city.

1938: At a time when freight is moved by rail and barges, Chicago is the country's second largest city, only losing that title to Los Angeles in the 1990s.

Today: Although they are still in the same state, Chicago has little in common with rural down-state towns like New Salem and Vandalia.

1830s-60s: Most black people in Southern states are slaves. Blacks living in states that bordered the Southern states are sometimes kidnapped and forced into slavery. The Supreme Court rules in 1857 that blacks can never become U.S. citizens.

1938: Although slavery is technically over when the Civil War ends in 1865, a series of laws passed in the South, known as Jim Crow Laws, keep blacks from enjoying their rights as citizens. Difficult IQ tests are given at polls to keep blacks from voting, and the charade of...