California also went through the Independence -> annexation process, though in California's case annexation happened pretty quickly post-independence. However, I will concede that those were the only two that actually got around to formally declaring independence; Hawaii was more like a coup, and the Sabine Free State was only de-facto independent.I don't really want to get into an argument about this, but from what you've put up there, only Texas and West FL did the "Declare independence and get annexed" thing, and Hawaii is close to that, but not quite; the others were purchased or conquered before anything like that happened. So, there are only two examples, which hardly makes a trend. The vast majority of American territory was purchased or outright conquered.
However, focusing too much on the question of independence is missing the forest for the trees; the main thrust of my argument was that US immigrants swamped into neighboring land with or without the permission of the owning powers, and this migration pattern frequently led to US annexation of said territory. In hindsight, it might have been better to use a broader term like saying that the settlers revolted in favor of the US.