The first Arbor Day took place in Nebraska City, Nebraska, on April 10, 1872. It is estimated that one million trees were planted that day. The idea of a holiday celebrating trees took hold; by the 1920s, every state in the US had passed a law stipulating that Arbor Day be observed on the last Friday in April. In Nebraska, it's observed as a civic holiday. Planting a tree is the most customary way to observe Arbor Day, but there are other ways to celebrate, too. Celebrate Arbor Day: Make it personal: Make this Arbor Day special by personalizing it to you. Enjoy the outdoors. Read More