Various local organizations are participating the Essex Heritage’s popular Trails and Sails event which runs for two weeks beginning Saturday. North Andover Historical Society’s 1789 Johnson Cottage is open both Saturday, Sept. 13, and Saturday Sept. 27, from 11 a.m. to 2 p.m. Those interested are asked to meet at the historical society’s headquarters at 800 Massachusetts Ave., North Andover. Spitalere also offers two Civil War Walks through Hilldale Cemetery on Friday, Sept. 19, and Friday, Sept. 26, at 2 p.m. Gather at the society’s headquarters at 800 Massachusetts Ave., North Andover.