1. On September 22, 1862, the Battle of Antietam took place in Sharpsburg, Maryland. This was the bloodiest single day in American history, with over 23,000 casualties. The Union Army was victorious, which led to the issuing of the Emancipation Proclamation a few days later.

2. In 1977, the Patapsco River flooded, causing widespread damage and destruction in the Baltimore area. The flooding was the result of a tropical storm that brought heavy rains to the region.

3. On September 22, 1955, the Baltimore Orioles played their last game at Memorial Stadium before moving to Camden Yards in 1992. Memorial Stadium was home to the Orioles for 38 seasons and also hosted the Baltimore Colts football team.

4. Frederick Douglass, the famed abolitionist and orator, was born on the Eastern Shore of Maryland on September 22, 1818. Douglass escaped slavery at the age of 20 and became a prominent speaker and writer, advocating for the abolition of slavery and equal rights for African Americans.

5. The Chesapeake Bay Bridge, which spans the Chesapeake Bay to connect Maryland's Eastern and Western Shores, opened on September 22, 1952. The bridge is over 4 miles long and remains a major transportation route in the state.