Answer:
Lexington's common is also known as Lexington green, it is the town of Lexington, Massachusetts.
It is the first site where the first skirmishes of battles of Lexington and Concord happened and which started the American revolutionary war. The common has been turned into a National Historic Landmark. The tension was building over the years between the British authorities and the American colonies especially in Massachusetts and when on April 18, 1775, British troops marched on Concord to seize the arms. A confrontation started with the colonialists, the British had to retreat. After this many more battles occurred and the colonialists became free.