1. On April 9, 1865, Confederate General Robert E. Lee surrendered to Union General Ulysses S. Grant at Appomattox Court House in Virginia, effectively ending the American Civil War. Maryland, as a border state, was deeply affected by the conflict and saw significant troop movements and battles throughout the war.

2. In 1783, on April 9th, Congress ratified the Treaty of Paris, officially ending the Revolutionary War and recognizing the United States as an independent nation. Maryland played a crucial role in the war effort, as it served as a major center of military and political activity and was home to key figures such as George Washington and Thomas Jefferson.

3. On April 9, 1718, the colony of Maryland was granted a royal charter by King George I, formalizing its status as a proprietary colony and granting it various privileges and rights. Maryland's founders had sought to establish a haven for English Catholics in the New World, and the colony's history has been shaped by the tensions and conflicts between religious and political factions.

4. In 1868, the state of Maryland ratified the 14th Amendment to the United States Constitution, which granted citizenship and equal protection under the law to all people born or naturalized in the United States. Maryland's ratification was one of the key steps in the amendment's adoption, which aimed to ensure civil rights for African Americans in the aftermath of the Civil War.

5. On April 9, 1917, Maryland's 5th Regiment National Guard was the first unit to arrive in Washington, D.C. in response to President Woodrow Wilson's call for troops to join World War I. Maryland would play a significant role in the war effort, mobilizing soldiers and resources to support the Allied powers and contributing to the eventual victory over Imperial Germany.