What year did the Great Chicago Fire occur?

The Great Chicago Fire occurred in 1871, making this the correct answer. This catastrophic event began on October 8 and lasted until October 10, resulting in the destruction of a significant portion of Chicago and leaving thousands homeless. The fire's causes have been widely debated, but it is often attributed to a combination of dry weather conditions, wooden buildings, and the city's firefighting limitations at the time.

The aftermath of the fire led to a comprehensive rebuilding effort in Chicago, which included the implementation of new fire codes and regulations, helping to improve urban planning and construction practices in the city. This event is an important moment in U.S. history as it highlights issues of urban development, disaster management, and community resilience.