"Hispanics" ........?

Hi, I was just wondering why Americans like to categorize hispanics as a race like white and black etc. Though many people in latin america are dark haired and dark skinned, there are also a lot of people with blonde hair and blues eyes, many asians, and many black people in many latin countries. A lot of Americans fail to recognize that many people in Latin america are a product of other cultures. For instance, I'm Argentinian, but my dads family immigrated to Argentina from Italy, and my mom is also born Argentinian but her grandparents were actually from Spain and the Ukraine. People would consider me "white" if they see me, but I always check off "Hispanic" or "latino" on papers and stuff. It's something I'm very proud of, being latino, but I can't help but feel weird about seeing "hispanic" or "latino" categories, I'm sure that's how many latinos like myself feel when they see such a broad category. It seems like many people think of hispanics and latinos like all looking the same, but really, in certain situations, grouping all latinos into one "race" would be like calling "American" a race.