To borrow a phrase, you are American by birth, Pakistani by the grace of God.
I've witnessed the same among some mixed English/American and Pakistani families. Upbringing is everything, and I've seen the mixed kids in these families range from successful high flyers, to losers and degenerates.
However, a common theme unfortunately is a loss of culture in most, and a complete inability to speak or understand Urdu. And most unfortunate of all is the inability of such families to instil Imaan (faith) or Islamic identity in their kids.
I've only seen one instance of an acquaintance in the US who married a white American woman, she converted to Islam, truly converted and not just superficially. Their kids alhamdulillah are all successful, well educated, well mannered, half American-half Pakistani Muslims. And from what I gather through conversations, such an upbringing required a lot of effort.