Would it be correct for me to say that the issue with racism varies quite considerably across the US?
I would definitely agree. Yes, there is racism everywhere. But it comes out in different ways in different places, and is better or worse in various areas.
If you're an interracial couple, then there are certain places you do NOT want to live. Consider:
* In many areas, it is standard practice to stop cars with a white man and a black woman (under presumption of prostitution). Getting stopped for "Driving While Black" was put under pressure recently in New Jersey, but it's still going strong in many other states.
* In the 21st Century, 40% of Alabama voted AGAINST removing a clause in the constitution banning interracial marriage. This is at the same time that a sizeable majority of Massachusetts voters are FOR gay civil union or marriage. Massachusetts is a viable state for an interracial couple to live; Alabama is not.