While i don’t do ancient history, i am currently in a history Ph.D. program at Johns Hopkins University.
I think it’s really important to make sure that you tailor your letters of application as closely as possible to each of the departments that you’re are applying to. Don’t be dishonest about your interests and your goals, but if your interests and goals coincide with those of the department, or of a particular faculty member, then that’s something you need to emphasize.
Make sure that your letters are also realistic about your ideas and intentions. While many schools expect you to have a pretty good idea of what you want to work on, a good school should also recognize that grad school is a time for learning new things. My own adviser says that she is actually sometimes a little cautious of people who apply to grad school claiming to know exactly what they want to write for their dissertation. She prefers someone who has some good ideas, but who is also open to taking on new ideas and exploring additional possibilities. Of course, other schools take a different approach, and expect you to hit the ground running with a topic already decided.
If you have closely researched which faculty member/s you want to work with, this might not be so important, but if you haven’t then being too specific about your interests can be something of a drawback, because you might find that there’s no-one who’s interested enough in your stuff to take you on.
Some people seem to think that the GRE is a really big deal. In my experience, history departments are not as strict as some other disciplines when it comes to the GRE. Of course, a good scroe is never going to hurt you, but it also won’t guarantee your acceptance if the faculty don’t think that you’re a good fit for the department. I’m not sure if the have an actual minimum acceptable score, but as long as you’re above a certain point they don’t actually take too much account of your exact numbers. For example, someone with a verbal score of 700 probably wouldn’t have any greater chance of getting in than someone with a verbal of 650.
My wife is in the same program as me, and before she decided to come here she turned down an offer from the History Department at Berkeley. Her GRE scores were in the range of about 620/620/620 for verbal, quantitative and analytical. That’s a pretty good score, but it’s not right at the top. My own scores were 760/770/800, because i’ve always had a facility for such tests. We’re both in the same program, and she’s doing just as well as i am. Most history departments recognize that getting through grad school takes more than decent GRE grades.
I can’t offer too much advice about your GPA issue. I came from Australia, which has a quite different grading system. On my application, i didn’t even fill in the GPA part; i just sent my transcripts (which had percentage grades) and let them work out the details. My wife had a GPA of 4.0. I do think, however, that your in-program GPA will be the thing they are most concerned with, and 3.68 is nothing to sneeze at.
I’ve spoken to a few professors in my department who have all been part of the admissions process, and they say that, once the quantifiable stuff like GPA and GRE of an applicant has been found satisfactory, the things they pay most attention to are the application letter itself, and the letters of recommendation. In the latter case, it certainly helps if your letters are written by people who are well-known in your field, or at least who are known to the people who will make the admission decision. I assume you have to send a writing sample with all these applications? If so, make sure that it’s polished and clear, and that it truly demonstrates that you can put a sentence together and sustain a complex argument.
I wasn’t able to visit all the grad schools before i decided, because i was living in Australia at the time. I did, however, manage to meet my current adviser when i came to the US on a research trip about a year before i started grad school. I think it’s good if you can meet your prospective professors or adviser before they even see you application, as this allows them to put a face to the application, and also gives you an opportunity to impress on them that you have the seriousness and maturity to undertake graduate study.
Finally, i know that this won’t be much consolation if you don’t get in, but the fact is that grad schools turn away dozens of well-qualified applicants every year. Here at Hopkins, about 12 students are typically chosen from a pool of over 200 applicants. Of those 200, probably more than half are good enough to succeed in the program. Hell, it’s the same at the undergrad level. I read an article recently in which they interviewed the admissions director for one of the Ivy League schools. He said, essentially, that getting into the popular schools is something of a crap-shoot, and that plenty of people who miss out are perfectly good candidates.
Good luck with the applications!