Since breast-feeding is best, why do most north american mothers bottle-feed their 6-month-olds?

It's the same way with the British and Australia (english speaking countries) and who knows what other countries. I know Americans get picked on for being different from the rest of the world but those who say "It only happens in America"never counted on the internet to reveal the truth...that America isn't quite so incredibly different from other countries. Back in the 1990s, people claimed that the worldwide weaning age from breastfeeding was 4 years old and America was so backward. On the internet we learn that Bangladesh (a third world country) has the highest weaning age in the world and it's barely 3 years old. So much for thinking that the worldwide weaning age is 4. You can't believe everything you read.

In order to understand this, you must take into account several factors. The culture and societal aspects of North America, and other westernized countries tends to shun open breastfeeding; mainly because of ideas of nudity. It's not forbidden and you are still allowed to do it, but these norms have stayed anyways. This would not be the same in, say more impoverished areas, where it is more socially and culturally acceptable. Also just because people don't breast feed doesn't mean that they aren't giving their baby breast milk in a bottle.

In regards to my last sentence, sometimes it can get painful when a young one chomps down. This is why some mother's just defer to using a bottle instead. 

Accessibility would be the correct answer