The world's oldest annual marathon will see the sport's elite athletes trying to carve out a legacy for themselves on Monday, as Boston's defending champion Hellen Obiri hopes to become the first women to "three-peat" in 26 years. Part of Boston's annual Patriots' Day holiday, this year's race coincides with the 250th anniversary of the battles of Lexington and Concord which kicked off the American Revolutionary War after Paul Revere's famous midnight ride. The British patrol intercepted Revere