1. In 1895, Minnesota became the first state in the United States to establish a system of public employment offices, known as job centers.

2. On April 20, 1912, the RMS Titanic, which had been carrying a number of Minnesota passengers, sank in the North Atlantic Ocean after colliding with an iceberg.

3. In 1939, Minnesota Governor Harold Stassen signed into law the first state sales tax in the United States, which went into effect on July 1 of that year.

4. April 20, 1971 marked the opening of the first Earth Day celebration, which was created by Minnesota native Gaylord Nelson.

5. On April 20, 1999, two students opened fire at Columbine High School in Colorado, resulting in the deaths of 13 people. While this tragedy did not occur in Minnesota, it had a significant impact on the state and the nation as a whole, leading to increased awareness of issues related to gun violence and school safety.