St. Mary's City is one of the most historic locations in the United States. Recognized as a National Historic Landmark since 1969, it is the best preserved founding site of a 17th-century English colony in North America. St. Mary's was the scene of many notable events in America's early history. Some of these are listed below:

First successful proprietary colony in English North America

First Freedom of Conscience policy in America

First effort to free religion from government in America  

First Catholic chapel in English America

First evidence of baroque town planning in America

First public inn in Maryland

First government building in Maryland (the Secretaries Office 1664)

First Protestant (Anglican) church in Maryland

The first official city in Maryland

Maryland's first state house, The Country's House

First monumental public architecture in Maryland, the 1667 Brick Chapel

First printer in the southern colonies of America.