The Maryland quarter shows the State House dome, located in Annapolis.  The dome is surrounded by branches of leaves from the state tree (White Oak) and the state's nickname ("The Old Line State").  Some people believe General George Washington gave the state this nickname as a way to honor the Maryland Line troops, who served in many Revolutionary War battles.

Maryland's State House is the oldest one still used regularly by a legislature.  Started in 1772, the building wasn't totally finished until 1797.  A lot happened during those 25 years to delay construction, including at least one hurricane and the Revolutionary War.  From November 1783 to August 1784, the Continental Congress met in the unfinished state house, using it to sign the Treaty of Paris that ended the Revolutionary War.