This is the top portion of the monument on Main Street in Nashua, NH erected in 1976 in celebration of the nations 200th birthday.
According to Wikipedia:
The phrase comes from a toast written by General John Stark on July 31, 1809. Poor health forced Stark, New Hampshire’s most famous soldier of the American Revolutionary War, to decline an invitation to an anniversary reunion of the Battle of Bennington and to send his toast by letter:
Live free or die: Death is not the worst of evils.