(CNN)The world might look a little greener on Friday.
That's because it's National Arbor Day, which people celebrate by planting elms, oaks, pines and basically any type of tree they can get their hands on.
Here's a brief look at how this day of tree appreciation came to be.
It literally means tree day
The Latin word for tree is arbor. True to its name, Arbor Day celebrates the preservation and planting of trees.
Arbor Day started in Nebraska
Nebraska was the first state in the US to observe it as a formal holiday in 1872. However, the Arbor Day Foundation says "tree planting festivals are as old as civilization."
Nixon recognized it as a holiday
"The planting of trees is an action that yields a long-range benefit on generations to come," Nixon, who created the Environmental Protection Agency, wrote in his proclamation. "Arbor Day uniquely symbolizes the truth that the earth belongs to every generation, not just ours."
Trees offer tons of benefits
Morton and his wife sought to plant trees in Nebraska to increase the amount of shade from the hot prairie sun. Trees also served as windbreaks, fuel and building materials.
Today, trees provide wildlife habitat, erosion control and natural beauty, the Arbor Day Foundation says.