1. In 1862, during the American Civil War, President Abraham Lincoln signed a bill abolishing slavery in the District of Columbia, which included parts of present-day Maryland.

2. On April 16, 1853, the Baltimore and Susquehanna Railroad was completed, which eventually connected Baltimore to Williamsport, Pennsylvania, and contributed to the growth of the transportation industry in Maryland.

3. In 1963, Maryland Governor J. Millard Tawes signed a bill officially designating the Chesapeake Bay Retriever as the state dog of Maryland, recognizing the breed's contributions to the state's hunting and fishing industries.

4. On April 16, 1900, Baltimore's Eubie Blake, a renowned jazz pianist and composer, was born. Blake became a significant figure in the early jazz scene and was the composer of famous songs such as "I'm Just Wild About Harry" and "Memories of You."

5. April 16, 2007, marked a tragic day for Maryland as a mass shooting occurred on the campus of Virginia Tech, which is located near the Maryland state line. The incident left 32 people dead and 17 injured, and it was one of the deadliest school shootings in U.S. history.