Four major fires break out on the shores of Lake Michigan in Chicago, Peshtigo, Wisconsin, Holland, Michigan, and Manistee, Michigan including the Great Chicago Fire, and the much deadlier Peshtigo Fire.

The Great Chicago Fire was a conflagration that burned in the American city of Chicago during October 810, 1871. The fire killed approximately 300 people, destroyed roughly 3.3 square miles (9 km2) of the city including over 17,000 structures, and left more than 100,000 residents homeless. The fire began in a neighborhood southwest of the city center. A long period of hot, dry, windy conditions, and the wooden construction prevalent in the city, led to the conflagration. The fire leapt the south branch of the Chicago River and destroyed much of central Chicago and then leapt the main branch of the river, consuming the Near North Side.

Help flowed to the city from near and far after the fire. The city government improved building codes to stop the rapid spread of future fires and rebuilt rapidly to those higher standards. A donation from the United Kingdom spurred the establishment of the Chicago Public Library.

Lake Michigan is one of the five Great Lakes of North America. It is the second-largest of the Great Lakes by volume (1,180 cu mi (4,900 km3)) and the third-largest by surface area (22,404 sq mi (58,030 km2)), after Lake Superior and Lake Huron. To the east, its basin is conjoined with that of Lake Huron through the narrow Straits of Mackinac, giving it the same surface elevation as its easterly counterpart; the two are technically a single lake.Lake Michigan is the largest lake by area in one country. Located in the United States, it is shared, from west to east, by the states of Wisconsin, Illinois, Indiana, and Michigan. Ports along its shores include Milwaukee and the City of Green Bay in Wisconsin; Chicago in Illinois; Gary in Indiana; and Muskegon in Michigan. Green Bay is a large bay in its northwest, and Grand Traverse Bay is in the northeast. The word "Michigan" is believed to come from the Ojibwe word ᒥᓯᑲᒥ michi-gami or mishigami meaning "great water".