Generally observed on the last Friday in April, Arbor Day is an unofficial US holiday designated as a day for planting trees. The holiday was founded by agriculturist Julius Sterling Morton, a Nebraska resident who believed that the prairies were in need of more trees to serve as windbreaks, hold moisture in the soil, and provide lumber for housing. To this end, he proposed that a specific day be set aside for the planting of trees. About how many trees were planted on the first Arbor Day? Discuss