I was somewhat surprised to see that he has become a naturalized American, because he certainly ranted about the US in 'Outposts' and it's impact on the "surviving relics of the British Empire". He was particularity upset about his treatment by the US administration on Diego Garcia when he showed up off shore in a sailboat. After all , the island is still a part of the British Empire, such as it is! In real life it is a strategic US military installation in the middle of the Indian Ocean.
He writes particularity well in describing the parts that allowed the United States to become just that, the UNITED States. Those parts range from Lewis and Clarke's expedition west - Jefferson went nuts when heard that a Canadian , Sir Alexander Mackenzie already had crossed continent and reached the west coast - so had Lewis and some what later Clarke make the same trip across the continent, to the impact of the Internet on current life - we can't live without it in to-days world, And we know much more about the world around us on a day to day basis.