1. Maryland became a British colony in 1632, when King Charles I granted the land to Cecilius Calvert, the second Lord Baltimore. June 12 is celebrated as Maryland's "Founders' Day" to honor the Calverts and the founding of the colony.

2. On June 12, 1776, the Continental Congress appointed a committee, including Samuel Chase and Thomas Stone of Maryland, to draft a resolution declaring independence from Great Britain. This resolution eventually led to the signing of the Declaration of Independence on July 4, 1776.

3. On June 12, 1864, Union troops under General Franz Sigel were defeated by a Confederate force led by General Jubal Early in the Battle of Lynchburg. This battle was part of the larger Shenandoah Valley Campaign during the American Civil War.

4. The Chesapeake Bay Bridge, connecting the eastern and western shores of Maryland, opened on June 12, 1952. This engineering feat spans 4.3 miles and is one of the longest continuous overwater steel structures in the world.

5. June 12, 2019 marked the 210th anniversary of the birth of Harriet Martineau, a British social theorist and writer who visited and wrote about Maryland in the mid-19th century. Martineau is best known for her pioneering work in feminist theory and as one of the first sociologists.