1. On August 12, 1688, the first organized protest against slavery in the American colonies took place in Germantown, now a neighborhood in Philadelphia. The Germantown Quakers issued a petition against the importation of African slaves, arguing that it was contrary to their belief in the inherent freedom of all human beings.

2. In 1833, the Maryland State Colonization Society was established on August 12, with the goal of transporting free African Americans to Africa as an alternative to slavery. The Society faced opposition from both abolitionists and slaveholders, and ultimately only a small number of people were resettled in Liberia.

3. On August 12, 1861, the Battle of Cedar Mountain took place in Culpeper County, Virginia, during the American Civil War. Maryland troops played a significant role in the Union victory, with the 5th Maryland Infantry and Baltimore Light Artillery helping to repel Confederate attacks.

4. The Chesapeake Bay Bridge, connecting the Eastern and Western shores of Maryland, opened to traffic on August 12, 1952. At the time, it was the world's longest continuous over-water steel structure, spanning 4.3 miles across the Chesapeake Bay.

5. On August 12, 1983, Baltimore Orioles first baseman Eddie Murray became the 27th player in Major League Baseball history to hit 300 career home runs. Murray, who spent 12 seasons with the Orioles, went on to hit a total of 504 home runs in his 21-year career.