Thanks to all for comments. LHLaw3 - sorry this is long - I think your son could certainly thrive at UVa if he has the opportunity. I don’t think he is any more likely to be in any danger there than anywhere else - whether it is big cities, the south, DC, New Hampshire, Chicago or California. It is a very tight knit campus - and that horrible march occured when students were away for summer break - and nothing like that would be allowed to happen again - now that the ugly provocateurs have been revealed. Cville is small, and though it has its normal small city crime/poverty issues - UVa is an oasis that embraces its students - all of them - and many of them are involved in the Cville community in service, mentoring, tutoring opportunities that enrich their lives and those of city residents.
At UVa there is a robust spirit of service and academics and social life, sports and volunteering that brings students together - all Students (again - bad apples/jerks/anti-social behavior can and does occur anywhere, on or off a campuses of course, and there is plenty of debate a UVa about all matters and how to move forward on them - but 99.9% of it is respectful and peaceful). There is a robust African American Affairs office and Dean of African American Affairs at UVa focused on recruiting and attracting and supporting black students - https://oaaa.virginia.edu/ . I think if you reached out, you and your son could be put in touch with current UVa students to hear their stories/successes/challenges. UVa graduates perhaps the highest percentage of african american students of any large elite University in the country - showing that they select excellent candidates and they nurture them along the way. As tuition and expenses have risen sharply in the past 10-15 years and the school has grown the percentage of african american students is less than it was in the 90’s when it was more than 10% - but in the past 5 years the percentage of first year students of color has been increasing showing UVa’s efforts at recruiting a diverse and representative population while seeking excellent candidates… https://alumni.virginia.edu/african-american-admission-enrollment-by-the-numbers/
In my time there into the mid 90’s I recall a very strong presence and activism of black students at UVa. (I came from a southern city majority black public high school that had been created after integration and had white flight into the 70’s so I was very in-tune to the black community at UVa - as a white kid from a black southern city high school (UVa’s social/fraternity/white social culture was foreign to me - but I found wonderful niches at UVa in and outside of that - and that’s when it was much smaller and more insular - today there are more and more diverse social sectors/communities at UVa). I do think UVa tries very hard for diversity and inclusiveness (and excellence within that) - within its student body and activities. If you take a look at historical graduation rates of black students, drop out rates, graduation/success/University integration of black student athletes into the University as a whole, student volunteering and activism, and look at current events and the black voices that are bubbling up and leading discussion and activism at UVa you will see there is a thriving - if not huge - black presence/life there - as well as integration within all of the many student groups at UVa too. But yes, this is America, issues of race/racism/history of oppression of blacks in America is and was everywhere, is still a challenge (more urgent with our nightmare “president”) and will take striving by all of us to change and perfect. But there is not some unique safety challenge to a black student at UVa than anywhere else.
I think UVa is the kind of place where your son could make his mark in society as a whole. Is it perfect? no Is his safety guaranteed anywhere he is (or any other person for that matter) ? no. But it’s a small college town, serene, peaceful and calm and even ‘boring’ the vast vast vast majority of the time - really all the time. It is a peaceful normal, sometimes inspiring and always challenging (in a good way) place to broaden his experience and develop him into an educated young man with many connections to others like him and different from him.
Do reach out to UVa deans/student affairs and see if they can put you in touch with some current black students to get their experience/thoughts.
best of luck to your family! 
here’s an uplifting opinion article by returning 4th year african american student after the awful riot/march in August
http://www.charlotteobserver.com/opinion/op-ed/article167070912.html