The PS Lady Elgin was a wooden-hulled sidewheel steamship that sank in Lake Michigan off Highwood, Illinois after she was rammed in a gale by the schooner Augusta in the early hours of September 8, 1860. The passenger manifest was lost with the collision, but the sinking of the Lady Elgin resulted in the loss of about 300 lives in what was called "one of the greatest marine horrors on record." Four years after the disaster, a new rule required sailing vessels to carry running lights.