This book is really interesting. I almost didn't know about the history of North America before the American Revolutionary War at all, so it was first time for me to hear the word "the United Colonies" in this book. If I thought about it, it would be quite natural that there were "the United Colonies" before the United States was formed, but I never thought about it before.
One of the reasons why I didn't know about the history of North America, is that the history of the conquests of Central and South America by Hernando Cortes and Francisco Pizarro were so dramatic and impressive. I've read about them a lot, but I was rarely interested in the history of North America. Cortes and Pizarro conquered the Aztec Empire and the Inca Empire with quite small bunch of soldiers in the fifteenth century, so I imagined that Pilgrims might conquer the natives in North America in a similar way, but it wasn't true.
Early Western colonists in North America in the seventeenth century settled just in the coastal regions of North America along the Atlantic Ocean, and they didn't conquer the natives but traded beaver furs with them. In the sixteenth century, a beaver hat became quite fashionable in Europe, and beavers in Russia was almost hunted to extinction. So colonists wanted to get beaver fur from the natives in North America, where beavers were abundant.
I guess that the Aztec Empire and the Inca Empire had been so centralized that Cortes and Pizarro could conquer with small soldiers because they just had to seize the Emperors. But the societies of the natives in North America were decentralized, and it was impossible to conquer them with small number, even if they had muskets. And through fur trade, the natives got muskets from Western traders, so it was more difficult to conquer them.
Mainly the colonists didn't fight with the natives, but colonist fought with each other. At first British colonists and Dutch colonists, who built New Amsterdam that is now New York, made a competition for fur trade. And then British colonists and French colonists competed, and in the end, British colonists and their home country fought with each other. After the French and Indian War and the Revolutionary War, the actual invasion into the inland of North America began.
Of course, there were frictions between British colonies, but they united against common enemies, Dutch and French colonists and their home country. The United States was based on the union of British colonies.
I wrote the entry "American Whaling and Japanese Modernization" about the book "Leviathan: The History of Whaling America", written by Eric Jay Dolin who wrote "Fur, Fortune, and Empire: The Epic History of the Fur Trade in America." This book is also quite interesting.