Agreed with PP on all counts. If you want to do private, there are many of them in the area, but it is questionable as to whether you will get a better education for your kids in private. There are plusses/minuses to both public and private. However, fyi - the privates are:

St. Agnes/St. Stephens
Burgundy Farms
Alexandria Day School
Brown Academy...

That's one of the best public schools in the region, and the neighboring Alexandria zones (Mason, Maury, Lyles-Crouch) are also excellent which is important in the event that MacArthur is over-enrolled. If you think socio-economic diversity is bad, you should consider leaving the region.

considering purchasing a house in Alexandria in Tylor run area and more specifically Quacker hill neighborhood. The elementary school listed is Mcarthur. My kid is 4, so he won't be attending school for another 2 years, but It is unlikely that we move in 2-3 years. So I was wondering if anyone knows anything about the quality of education in Mcarthur? Does the same concern that many parent have about other Alexandria schools(such as socioeconomically diverse population) apply there too? Any first hand experience and finally what private elementary school do you suggest if we decide to choose private?

Thank you