The first Arbor Day is celebrated in Nebraska.

The Spanish village of Mondoñedo held the first documented arbor plantation festival in the world organized by its mayor in 1594. The place remains as Alameda de los Remedios and it is still planted with lime and horse-chestnut trees. A humble granite marker and a bronze plate recall the event. Additionally, the small Spanish village of Villanueva de la Sierra held the first modern Arbor Day, an initiative launched in 1805 by the local priest with the enthusiastic support of the entire population.

While Napoleon was ravaging Europe with his ambition in this village in the Sierra de Gata lived a priest, don Juan Abern Samtrés, which, according to the chronicles, “convinced of the importance of trees for health, hygiene, decoration, nature, environment and customs, decides to plant trees and give a festive air. The festival began on Carnival Tuesday with the ringing of two bells of the church, and the Middle and the Big. After the Mass, and even coated with church ornaments, don Juan, accompanied by clergies, teachers and a large number of neighbours, planted the first tree, a poplar, in the place known as Valley of the Ejido. Tree plantations continued by Arroyada and Fuente de la Mora. Afterwards, there was a feast, and did not miss the dance. The party and plantations lasted three days. He drafted a manifesto in defence of the trees that was sent to surrounding towns to spread the love and respect for nature, and also he advised to make tree plantations in their localities.
—Miguel Herrero Uceda, Arbor Day

The first American Arbor Day was originated in Nebraska City, Nebraska by J. Sterling Morton. On April 10, 1872, an estimated one million trees were planted in Nebraska.

Birdsey Northrop of Connecticut was responsible for globalizing the idea when he visited Japan in 1883 and delivered his Arbor Day and Village Improvement message. In that same year, the American Forestry Association made Northrop the Chairman of the committee to campaign for Arbor Day nationwide. He also brought his enthusiasm for Arbor Day to Australia, Canada, and Europe.