When it comes to food, there are some strict rules to follow, so don't even think about sneaking in that extra jar of jam or block of cheese. The US has some serious food safety regulations, and you don't want to get caught with a contraband sandwich in your luggage. Seriously, though, check the USDA website for the latest on what's allowed and what's not.
On the other hand, if you're bringing gifts for your American friends, you're in luck, because most personal items are allowed, as long as they're not prohibited or restricted. Just be sure to declare everything on your customs form, or you might find yourself in a world of trouble. And trust us, you don't want to mess with US Customs – they're like the superheroes of border control.