Columbian Exchange and today is eaten not only in Brazil and the rest of Latin America but also in Africa, the Indian Subcontinent and Southeast Asia.
Graviola (Annona muricata) is truly a fruit of the tropics, and temperatures of 5C (40F) can be sufficient to kill a tree. In the USA it is only in the Keys of Florida, in the Caribbean Islands and Hawaii where cultivation of the graviola is possible. In Brazil, the tropical northeastern region of the country is the center of graviola cultivation and commercialization.
Graviola can be eaten as-is, though pulling apart the flesh, extracting the seeds and eating the flesh tends to be a very messy business. It is more often eaten after some sort of processing - as frozen fruit pulp, as a freshly-made fruit juice, or as a flavor for mousses, ice creams, or yogurt.
Because the fruit is heavy (it can weigh up to 15 lb - 7 kg) very quick-ripening and fragile there is little market for export of the fresh fruit to areas outside the tropics. The juice can be canned or concentrated and frozen and these products can often be found in Latin American or Asian grocery stores in Europe and North America.
Just as nothing compares to a ripe, juicy strawberry that has just been picked and is still warm from the sun, the true luxuriousness of graviola can only be experienced by opening a ripe fruit, using one's hands to pry apart the creamy sacs of flesh to remove the seeds then popping the flesh into one's mouth and rolling it around with one's tongue before swallowing. For that, you'll have to come to Brazil, or go somewhere else in the tropics. And during this season of bitter cold and heavy snows in the Northern Hemisphere is that a bad thing?