1920: The year that Main Street is published, the Nineteenth Amendment to the Constitution grants the vote to women.

Today: Voting rights are strictly enforced. Women are considered a powerful political bloc that politicians try to gain support from.

1920s: The first commercial radio broadcast signal is sent out of KDKA in East Pittsburgh, using a technology that will eventually allow people from coast to coast to share a common experience simultaneously.

Today: Many low-wattage local radio stations are available across the world via the Internet.

1920s: A town like Gopher Prairie could hire an advertising consultant to design a brochure that exaggerates the town's features, hoping to lure prospective businesses.

Today: Small towns are even more likely to hire media consultants to help polish their images.

1920: The national prohibition against alcohol, mentioned in the novel's final pages, goes into effect on January 16, in accordance...