ARBOR DAY. On the motion of the agriculturist J. Sterling Morton, the Nebraska State Board of Agriculture designated 10 April 1872 as a day to plant trees, naming it Arbor Day. Morton had moved to the Nebraska Territory in 1854, and he quickly tried to remedy the treeless conditions of the plains. In 1875 the state legislature changed Arbor Day to 22 April, Morton's birthday, and made it a legal holiday. It is now observed in every state except Alaska, usually on the last Friday in April. Arbor Day is also a legal holiday in Utah and Florida, although Floridians observe it in January.
Olson, James C. J. Sterling Morton. Lincoln: University of Nebraska Press, 1942.
Schauffler, Robert Haven, ed. Arbor Day: Its History, Observance, Spirit and Significance, with Practical Selections on Tree-Planting and Conservation, and a Nature Anthology. New York: Moffat, Yard and Company, 1909.
Ar·bor Day • n. a day dedicated annually to public tree-planting in the U.S., Australia, and other countries. It is usually observed in late April or early May.