Africanized Honey Bees are not native to the U.S. but they have made their presence known in the states of California, Texas, Nevada, New Mexico, Arizona, Oklahoma, Louisiana, Alabama, Florida, and recently Tennessee. Theses honey bees continue to migrate north but at a much slower rate than when they first were released in South America. Geographical barriers and climate deter their expansion in other areas of the country.
Generally, Africanized bees are not a threat if you keep your distance from a the hive and do not disturb the nest.
Below is the confirmed Africanized territories map (modeled after the USDA Africanized map) and some facts compiled together to illustrate the behaviors and differences of Africanized & European Honey Bees. Although, the physical appearances of these two bees are indistinguishable, you can see a drastic difference in their personality characteristics.