Do they need passports?One thing at a time.
What? South Koreans don't even need a tourist visa to enter the United States. Are we favoring the Asians? Citizens of Canada traveling to the United States do not require a nonimmigrant visa. Mexico is part of North America but Mexicans are treated differently than Canadians why? Central Americans and South Americans need an entry visa as well. Have you ever heard of the visa waiver program? 36 countries participate in this program that allows travel without visas into the US. None of them are in the Americas. http://travel.state.gov/visa/temp/without/wit...
As for why the heightened visa requirements on those south of the border, perhaps it has something to do with them holding down five of the ten spots from which illegal aliens hail.