The mansion at the Arbor Lodge State Historical Park in Nebraska City, Nebraska. A simpler iteration of this later expanded great house on these grounds was the place where newspaper editor and tree lover Julius Sterling Morton hatched the idea for Arbor Day — the ceremonial holiday (people don't take off work to mark it) that encourages people to plant and care for trees. On the holiday's first official day, celebrated just in Nebraska on April 10, 1872, more than 1 million trees were planted. Photo by Carol Highsmith, 2021.