I'm starting work in the US, and I'm wondering if my credit history will transfer. If not, is there a way for me to gain an "international" credit history, or equivalent, in expectation of other future moves?
Currently the credit history are not International but are local.
Many countries don't have a concept of credit history yet.
Having said that, if you are moving to US, depending on your history in your country, you can ask the same bank to provide you with a card and then start building history. For example in India I had a card with Citi Bank and when I moved to US for a short period, I was given a card based on my India Card, with equivalent credit in USD.
If you are moving often internationally, it would make sense to Bank with a leading bank that provide services in geographies of your interest [Citi, HSBC, etc] and then in a new country approach these institutions to get you some starting credit for you to build a history.
It's not just that credit history is local; it's that it's a private business run for profit.
The "big three" credit bureaus in the US are Experian, Equifax and Transunion. They collect information on debt usage and abuse from various companies in the US, and charge a fee to provide that information (and their judgement of you) to companies interested in offering you further credit. But there's nothing stopping a company from collecting international credit histories, or specialized credit histories either (for instance, there's a company called ChexSystems which focuses on retail purchase financing (mostly auto) and checking account abuse, while ignoring other types of lending).
That being said, I don't know of any companies which currently collect international credit histories. Perhaps in Europe, with more nations in close geographic proximity, there would be, but not in North America.
Credit history is local, so when you move to the US you start with the blank slate. Credit history length is a huge factor, so in the first year expect that nobody would trust you and you may be refused credit or asked for deposits. I was asked for deposits at cell phone company and refused for store cards couple of times. My advice - get a secured credit card (that means you put certain sum of money as a deposit in the bank and you get credit equal to that sum of money) and if you have something like a car loan that helps too (of course, you shouldn't buy a car just for that ;) but if you're buying anyway, just know it's not only hurting but also helping when you pay). Once you have a year or two of the history and you've kept with all the payments, you credit score would be OK and everybody would be happy to work with you. In 4-5 years you can have excellent credit record if you pay on time and don't do anything bad.
If you are working it the US, a lot of help at first would be to take a letter from your company on an official letterhead saying that you are employed by this and that company and are getting salary of this and that. That can serve as an assurance for some merchants that otherwise would be reluctant to work with you because of the absence of credit history. If you have any assets overseas, especially if they are held in a branch of international bank in US dollars, that could help too.
In general, don't count too much on credit for first 1-2 years (though you'd probably could get a car loan, for example, but rates would be exorbitant - easily 10 percentage points higher than with good credit), but it will get better soon.