White people of America

I have lived a few places in the USA in my short lifetime...Mobile, AL...Tuskegee, AL...West Palm Beach, FL...Southfield, MI...Hartford, CT...Dallas, TX...Washington, DC...and I have had the pleasure of visiting many other fabulous cities. There is one thing I have notice in all of these cities as I have driven through them...White people in general do not have curtains, blinds, shades or even sheets hanging at the windows! Why is that? You may be wondering how I know the people that own the homes, rent the apartments, live in the space are white...because I can see them! Could someone please explain the cultural oddity?