A lot of people remember that the US Government got involved with poppers way back when. There was a time when the FDA got involved and fined a company for 'mislabeling' their products. The FDA never made it illegal to sell or use poppers. During the AIDS epidemic, many states and cities looked at outlawing poppers because they considered them to lead people to risky sexual behavior. But since....we have learned how to control risky behavior (use condums).
In Canada, it is now illegal to sell poppers but not illegal to possess or use them. Recently, poppers were challenged in the UK but after a gay Member of Parliament, who admitted to using poppers convinced Parliament that they were not dangerous and so the proposed law was not passed.
Why 'Made in the USA' - you will find lots of cheaper products on the internet but you need to be careful as these made be cheap knock offs from China - often made with jet fuel - which is dangersous to use.