1. December 31, 1862: Maryland abolishes slavery
On December 31, 1862, Maryland's General Assembly passed a new constitution that abolished slavery in the state. This was a significant moment in Maryland's history, as the state had been deeply divided over the issue of slavery for many years.

2. December 31, 1983: Baltimore's first female mayor takes office
On December 31, 1983, Baltimore's first female mayor, Mary Pat Clarke, took office. Clarke served as mayor from 1987 to 1995 and was known for her focus on improving education, public safety, and housing in the city.

3. December 31, 2005: Maryland football wins Champs Sports Bowl
On December 31, 2005, the Maryland Terrapins football team won the Champs Sports Bowl by defeating the Purdue Boilermakers 24-7. This was the Terrapins' first bowl victory since 2002 and marked a successful season for the team.

4. December 31, 2013: Same-sex marriage becomes legal in Maryland
On December 31, 2013, same-sex marriage became legal in Maryland. The state's General Assembly had passed a same-sex marriage bill earlier in the year, and it was signed into law by Governor Martin O'Malley. Maryland became the eighth state to legalize same-sex marriage.

5. December 31, 2020: Maryland surpasses 5,000 COVID-19 deaths
On December 31, 2020, Maryland surpassed 5,000 COVID-19 deaths since the start of the pandemic. This was a somber milestone for the state and served as a reminder of the toll that the pandemic has taken on communities across Maryland and the United States.