1. In 1861, Minnesota Governor Alexander Ramsey proclaimed April 19 as a day of fasting and prayer for the state and national government as tensions escalated between North and South, leading up to the American Civil War.

2. On April 19, 1880, famed author and naturalist John Muir arrived in Minnesota on a tour of the Midwest, during which he advocated for the protection of natural areas and for the establishment of national parks.

3. In 1919, a major labor strike known as the "Great Steel Strike" began on April 19, involving over 350,000 workers nationwide, including those in Minnesota's iron range, who were protesting for better working conditions and wages.

4. The University of Minnesota's highly regarded Department of Earth Sciences was founded on April 19, 1949, and has since become a leading center for research and education in the fields of geology, geochemistry, and geophysics.

5. On April 19, 1971, the first Earth Day was celebrated across the United States, including in Minnesota, as a grassroots effort to raise awareness about environmental issues and promote sustainable practices. Today, Earth Day is observed annually on April 22.