1. Maryland became the 7th state to ratify the Articles of Confederation on July 17, 1778. The Articles were a precursor to the United States Constitution and established a loose alliance of the 13 original states.

2. On July 17, 1864, the Battle of Monocacy occurred near Frederick, Maryland during the American Civil War. Union General Lew Wallace and his troops delayed Confederate troops under General Jubal Early, allowing forces under General Ulysses S. Grant to reinforce Washington D.C.

3. The Chesapeake-Potomac Hurricane struck the region on July 17, 1936, causing significant damage and flooding in Maryland. The storm caused over $3 million in damage and is considered one of the worst hurricanes in the region's history.

4. Pimlico Race Course, located in Baltimore, Maryland, held its first ever horse race on July 17, 1870. The track is home to the Preakness Stakes, one of the three major horse racing events in the United States and the second leg of the annual Triple Crown.

5. On July 17, 1989, the USS Maryland, a nuclear-powered submarine, was launched from the Electric Boat Division of General Dynamics in Groton, Connecticut. The submarine was named in honor of the state of Maryland and has since participated in numerous military exercises and missions.