The Edgewater Historical Society, as part of its 25th anniversary celebrations, will host Lawrence Okrent, author of "Chicago from the Sky: A Region Transformed," at 10 a.m. March 16 at the Broadway Armory, 5917 N. Broadway. Okrent is a noted urban planner and pilot. His book of aerial photos documents 25 years of development in the Chicago region. His presentation will include many of his unpublished aerial photos of Edgewater and the north lakefront.