1. In 1897, the precursor to Dow Chemical Company, the Dow Process Company, was incorporated in Michigan. The company went on to become a prominent worldwide chemical manufacturer with a significant presence in the state.

2. On July 21, 1934, Depression-era bank robber John Dillinger was shot and killed by FBI agents outside the Biograph Theater in Chicago. Despite not occurring in Michigan, the incident had a significant impact on the state as it helped to solidify J. Edgar Hoover's reputation as a crime fighter and inspired several Hollywood films.

3. Founding member and keyboardist of the rock band The Doors, Ray Manzarek, was born in Chicago on July 21, 1939, but grew up in Michigan. The band gained significant popularity in the late '60s, and Manzarek continued to be a prominent figure in the music industry until his death in 2013.

4. In 1955, the historic Mackinac Island State Park Commission was established, specifically tasked with the care and preservation of Mackinac Island's natural and cultural resources. Today, the park remains a popular destination for tourists and Michiganders alike.

5. On July 21, 1972, the U.S. Environmental Protection Agency (EPA) announced the first national air quality standards for six common pollutants, including sulfur dioxide and carbon monoxide. This announcement was significant for Michiganders, as the state has a long and complex history with industrial pollution and its impact on human health and the environment. The EPA's efforts have played a crucial role in mitigating air pollution in the state and across the country.