Referring to which part?

Q: Manifest Destiny was the idea where it was United States destiny to expand its borders across the whole of North America (expand west), and to extend and enhance its political, social, and economic influences, as well as preventing further European colonization. Was John O'Sullivan's important quote “our manifest destiny to overspread the continent allowed by god for the free development of our yearly multiplying millions”? So in this context, when he writes "overspread", he refers to just some of the continent, but not all, right?

A: Yes! Very well said!

What is he referring to "Yes" about? What is he referring "Very Well said" about?

I think he is referring "yes" to my question about the quote, and very well said to my initial clarification.