March 17th is most commonly associated with St. Patrick's Day, but here in Suffolk County, Bostonians also know this date as Evacuation Day. Students at the Perkins Elementary School in South Boston recently asked, "So what is Evacuation Day anyway?" With help from their teachers, the students have produced a book that explains the significance of the day in text and images. They learned that the events surrounding Evacuation Day -- when British troops fled Boston during the American Revolution -- took place just steps from the Perkins School, in the Dorchester Heights section of South Boston. Pictured here (click to enlarge) is a map of the area at the time, showing the positioning of British and American troops.