Where did these big, friendly, smart cats come from?

I've read numerous articles about the alleged origins of Maine Coon cats. My conclusion is that Maine Coons are some combination of Turkish Angora, Norwegian Forest Cat (or its ancestor) and other long-haired domestic cats from Europe. When Europeans came the North America in the 17th century, they brought cats on their ships. They were useful for controlling the mice and rats that accompanied bags of grain. Then they became farm cats and feral cats in towns. People made them pets. The long-haired among these cats adapted to the climate in the North East of the US and became the large, long-haired, friendly cats we now know as Maine Coons.