1) On April 27, 1861, Maryland militia members attacked a regiment of Union soldiers as they marched through Baltimore during the Civil War. The incident, known as the Baltimore Riot of 1861, resulted in the deaths of four soldiers and twelve civilians, and marked a turning point in Maryland's loyalties during the war.

2) in 1908, the first airplane flight in Maryland took place on April 27th. Glenn Curtiss, a famous aviator at the time, piloted a plane over the city of Baltimore and landed safely in a field outside the city.

3) April 27, 1926 marked the opening of the Carceral Institution for Women in Jessup, Maryland. The facility, which was the first women's prison in Maryland, housed female inmates until its closure in 1991.

4) The Battle of Snow Hill occurred on April 27, 1782, during the American Revolution. Loyalist forces attacked the town of Snow Hill in Worcester County, Maryland, but were ultimately repelled by a group of Patriot defenders.

5) On April 27, 1941, the USS Nantucket, a training ship for the Maryland State Naval Defense Force, was launched in Baltimore. The ship served as training vessel for naval officers throughout World War II before being decommissioned in 1947.