omerville is home to the first American flag, or at least one of them. The Grand Union Flag was flown by George Washington on Jan. 1, 1776, to rally the fledgling Continental Army. The history of this flag is complex and interesting, and the flag remains a centerpiece of Somerville's historical identity. This year, Somerville celebrates its 175th birthday as an independent city (it was part of Charlestown until 1842), and there is a special event to commemorate the Grand Union Flag.