historyperson

US PhDs are more competitive on both sides of the Atlantic (at least in US history), and certainly more competitive in the US. Especially when your US PhD options are Penn or Princeton. Doing coursework and comprehensive exams will prepare you to teach, which is what most professorships emphasize. The US degree will serve you better by setting you up for a broader range of options. While non-academics can be impressed by European institutions on your CV, in my experience most historians recognize a US degree as a better indicator of depth and breadth of training. And it's other historians who will be evaluating you for a job, if you want to enter academia. It's still possible for you to give yourself that depth and breadth on your own, and to be an impressive historian, coming out of a UK institution. But in the early going, you will have to work harder to demonstrate that you can teach, know your field well, etc., and I don't see a great reason to put yourself through that if you don't have to. The only caveats: if your archives are all in Europe, yes, there's an advantage to basing yourself in the UK--when it comes time to research. In my mind this is still a secondary concern to having coursework, comps, and a longer, more competitive program in the US, especially if your US program options have some guaranteed fellowship years (no teaching) where you can base yourself in the UK for a research year or two. I'd imagine Princeton, at least, is good at this. If your 100% perfect advisor is in the UK, and your American advising options don't feel quite right, that's another reason to consider a UK degree over an American one, as advisor fit is the most important factor when deciding between reasonably funded offers. And, of course, if you have personal reasons for wanting to be in the UK, you're in the best position to make that judgment call. But if your goal is a tenure track job in a history department, my money is on the US degree as the easiest, most competitive way forward. There are great postdoc opportunities in the UK and Europe, which would likely be the most beneficial way to get some time in the UK into your career. (all with a caveat that I don't know the History of Science job market) (and that getting a terminal MA in the UK can be a great option for boosting an application--my comments pertain only to a US vs. UK PhD dilemma)

Work experience outside of academia can be a real advantage when applying to history PhD programs. It shows that you have experienced the non-academic working world--suggesting that you have the maturity and perspective to know why you want a PhD, and to know that you are training for the jobs you most want. While some people come straight from undergrad into a PhD program and do well, those who have gotten away from school tend (from what I've seen) to complete the degree with greater frequency, and to have an easier time treating grad school as professional training (which it is) vs. continuing undergrad (which it is not). Your personal statement is your chance to explain your path to your career decision. Tell that story as a strength, not as an apology. Where your background suggests potential weakness, to me, is your writing sample. All programs--especially top tier ones--want to see evidence that you can research and analyze history with primary documents, situated within a historiography. This becomes even more crucial when you are applying to history programs with your primary training in other fields (sociology and law). I was in a similar situation, with a major and a thesis in a non-history field. To address this, I audited a research seminar taught by a historian, and researched and wrote an article-length piece of original research, in order to have a strong writing sample. This also helped me to develop a research project to pitch in my personal statement. During the same year, I paid for language training at a local college--it cost less than $2,000 for the year, much cheaper than a MA. I was able to keep working part-time during this year, and probably could have worked full time if it had been necessary. A MA will give you the credential, plus more structure and mentorship, along with a usable history writing sample. Depending on your finances, it's probably the most thorough way to prepare yourself to apply for a PhD. But there are less expensive ways to boost your profile.

Ask your potential advisor to put you in touch with current UVA grad students. Also, if you want to visit the campus, let your potential advisor know that UVA's visit day funding won't cover your expenses, and you don't think you can afford the out of pocket costs--but that you would like to visit. Some faculty have extra funds or might find another way to bridge the financial gap. It's worth a try. I think it makes a big difference to visit in-person, even if you doubt it will change your fundamental decision to accept. It helps you to find housing and housemates, and lowers the stress of unknowns when you make your move and start the program. Even if you are pretty sure you've made up your mind, it helps to have a concrete sense of what the place looks like, who you'll be around, get a feel for the culture, etc. If you are unable to come to campus, talk to multiple current students about your program and life in Charlottesville--especially, get housing advice. You can recover from making a housing mistake the first year, but it can be a real pain while you wait out a lease you regret.