The use of name "Buckeye" to refer to an Ohioan dates back to the 18th century. The people and the prolific plant became synonymous, especially after Ohioan William Henry Harrison ran for president. The nut of this tree was so named because its shape, size and color resemble a the eye of a buck deer.  In 1953, the Buckeye State became Ohio's official nickname. It's also the name of one of the state's iconic treats.