Arbor Day was originally proclaimed a state holiday in Nebraska (of all places) in 1874 by Governor Robert W. Furnas, and it was observed on April 10th that year. More on the holiday's history can be found HERE -- and be sure not to confuse it with "Our Boar Day," proclaimed a state holiday in West Virginia in 1926 by Governor Bucephelus Huck, a day that set the precedent for West Virginians to take road kill home for dinner (as long as it was within 24 hours).
In tribute to Arbor Day, Emmett Lee Dickinson (Emily Dickinson's third cousin, twice removed -- at her request) penned a short poem honoring trees (below on the left). His poem inspired third cousin Emily to pen her poem, "An Hour is a sea" (below on the right).
By Emmett Lee Dickinson: What Power has a Tree In great variety – What awe the Arbor be – | By Emily Dickinson: An Hour is a Sea Between a few, and me -- With them would Harbor be – |