"pertaining to Spain" (especially ancient Spain) 1580s, from Latin Hispanicus, from Hispania "Iberian Peninsula," from Hispanus "Spaniard" (see Spaniard). Specific application to Spanish-speaking parts of the New World is from 1889, American English; since c. 1972 especially applied to Spanish-speaking persons of Latin American descent living in the U.S. As a noun meaning "Hispanic person" from 1972.
Others are reading
<a href="https://www.etymonline.com/word/Hispania">Etymology of Hispania by etymonline</a>
Harper, D. (n.d.). Etymology of Hispania. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/Hispania