I wouldn’t necessarily, hence my query. I suppose a real answer to my question would be “Some stayed, some left, some still look Chinese, some don’t, and a smattering of ‘other.’”
See here
Loewen’s book details some rathe grisly progroms propoated against the Chinese in the late 19th Century. PRobably explains why Chinese populations are not more widespread.
Here’s a link to some information on the Chinese who settled in Mississippi in the early-mid 1900s. It’s mostly about race relations between blacks, whites and the Chinese, but also talks of a movement in the Chinese community to convince men to abandon any half-black children they had fathered, to help speed up integration. So, there are descendants of these people out there who’d be invisible to you. As a famous (sort of)* example, look at the 1/4 Chinese Tyson Beckford. His eyes are the only hint, and in your question about the railroad workers, you’d be looking for people who’d often be much than 1/4 Chinese.
*It’s not really the same thing because I don’t think the Chinese grandmother was an American immigrant.
Growing up in the San Francisco Bay Area, I couldn’t understand how Asians could be considered a minority, seeing as they seemed to make up more than half of my school. Many of these students were Chinese. I was aware of San Francisco’s Chinatown and knew that other cities had smaller Asian neighborhoods of their own. Like any child, I assumed my surroundings were the norm. It sure is different here in Reno, where the city fathers deliberately burned down Chinatown.
Is John posting like Rumsfeld talked? Indeed. Is it scaring me? Yes. 
I suspect that in many of the suburbs, like where I live, later immigrants are much more prevalent than the older, more established immigrants. There are a lot of stores and businesses dedicated to native Chinese speakers in the Valley. I know of several people who brought their parents over, who haven’t learned English, even though the children went to grad school here.
Funny you should mention DC. While the District has a neighborhood called Chinatown, no more Chinese-Americans live there than any other neighborhood (although there are more Chinese restaurants, but just barely).
There are Asian enclaves out in the suburbs; Vietnamese in Falls Church and Springfield, Koreans in Annandale and Merrifield. Not a huge concentration of Chinese, though. And very few of the 2nd-3rd generation Chinese I’ve known are married to other Chinese spouses, so their children look about as Asian as Keanu Reeves. Chinese America is a casualty of the “Melting Pot.”
Friends of mine in California are respectively third and fourth generation Chinese. His great-great grandfather came to work on the railroads in the 1850s. Because their ancestors married other Chinese, they look like … well … Chinese … and so do their kids … go figure. Her sister is the Chief of Police in San Francisco, they’re good folks. Don’t know what the other “Chinese traits” might be that you’re referring to.
w.
I remember reading something about how the early Chinese were males, which led to a demand for females.
Nature abhoring a vacuum, Chinese females were indentured (effectively slaves) imported illegally and forced to work in brothels. Since the business was profitable, American officials were paid off.
This led to elopements, which was pretty dangerous, as the brothel keepers resented what they considered shoplifting.
I can’t remember where I read it, probably a newspaper book review, but it could jog someones memory.
minor nitpick: there was never a “Chinese exclusion act.” There were multiple bills and laws passed at excluding the Chinese and other Asians, and these came collectively to be commonly known as the "Chinese exclusion acts. Not that that has much to do with the price of rice or anything, but this is a board fighting ignorance.
My old hometown of Tacoma Washington has a black mark on its name IRT the Chinese
I too am wondering what Chinese traits the OP is asking about that would be lost through assimilation, like…mothers-in-law forgetting to hate their son’s wives? (D&R!!!)
I grew up in the Bay Area too, and the OP interested me, because although it’s true that I have known plenty of people of Chinese descent (my best friend for years and years was Chinese-American and through her I got invited to lots of Chinese cultural, uh, stuff), they were inevitably immigrants or the childen of immigrants. But I never really thought about that until now.
I’ve known a few people who had one Chinese grandparent, though. That ancestor must have been in the US quite awhile ago. Like a girl I knew in HS whose last name was Chen, had only the slightest Asian features.
Sorry for the hijack, but are the Portuguese not considered Caucasian?
Well, they’re certainly below the commonly accepted Mediterranean Line of Swarthiness.
Perhaps they are hanging out with the baby pigeons. 
Not really. The history of the plantations I’ve always heard distinguished between the Caucasians and the Portuguese. The Caucasians hailed not only from Europe; some were born in the US and Hawaii. Today, “Caucasian” is understood as your average white guy. The Portuguese came from Portugal. Most people will picture a person with dark hair and a slightly darker skin tone when they hear “Portuguese.”
Did I think about that before I hit the submit button? Yes. Did I think anyone else would notice? No. 
There’s a few here.