That's true, but my blog is not a peer-reviewed publication, it is a personal journal, and as such my policy is not to make substantial changes to posts after they're published. I want my blog to be a reliable representation of who I am (or, in this case, who I was) warts and all. Sometimes I'll post corrections and updates, and maybe I will in this case, but geez, it's a twelve-year-old post and this is the first time anyone has brought this up. This probably isn't be the most egregious uncorrected error I've ever made.
I don't think it would be as trivial to fix as you think. I can't just say, "This is Gibbs's position, not mine" because I don't actually know that to be a fact. This happened 12 years ago, and my recollection could be wrong. It's entirely possible that this was actually my position at the time and I just don't remember. So before I can confidently attribute this position to Gibbs I'd have to verify that this was indeed Gibbs's position at the time, and that seems like a non-trivial undertaking.
I'll tell you what, though, if you can find a reference that this really was/is Gibbs's position I will make the correction.
It is trivial. No one's expecting you to find and state the exact current state of the literature, just to clarify that you were overstating the case at the time.
The problem is, you stated it as undisputed fact, when you didn't actually know it to be. Posters are only asking you to correct that overconfident "fake it til you make it" misrespresentation.
"Update: I was going off of my memory of the literature at the time, it turns out I was just parroting what I understood Gibbs's position to be; there are good reasons to believe China wasn't a major factor."
That didn't seem so hard. OTOH, if you're just optimizing for sounding confident and smart, I guess none of that matters. But you've spent at least as much effort complaining about changing as it would have taken to correct it.
Fair enough, I will fix this one way or another. Thank you for your patience. (Just out of curiosity, why do you care about this enough to put so much effort into persuading me? Surely this is not the most destructive bit of misinformation floating around on the internet?)
P.S. I decided to actually look into the actual fact of the matter, and it appears Gibbs's claim may actually have some merit:
"[The] chief promoter of a transcontinental railroad was Asa Whitney, a New York merchant active in the China trade who was obsessed with the idea of a railroad to the Pacific. In January 1845 he petitioned Congress for a charter and grant of a sixty-mile strip through the public domain to help finance construction." [Emphasis added]
The article doesn't specifically say that China was the principal motivation, but in 1845, before the discovery of gold in California, there weren't many other reasons to build a transcontinental railway. And since the railroad didn't actually get built until long after the gold rush was well underway, the actual motivation is probably a mix of different factors. But given Whitney's role, the idea that China was a factor seems like it could turn out to be defensible after all.