TL;DR for those put off by the giant block of un-paragraphed text: The ancient Romans didn't have a 'U' letter, and used 'V' instead. 'U' didn't enter widespread use in English until the 18th century. Courthouses are often designed in a neoclassical style and sometimes use 'V' for 'U' as part of the throwback style.
Which is why 'W' actually looks more like a "double V".
TL;DR Homage to Latin
Living in the US (I am American born here) I have always noticed that things foreign seem to be more important than things domestic. Not everything but enough things (food, design, furniture, language, liquor) that I was of aware of this even as a kid. An exception might be Universities a possible exception to that would be Oxford and Cambridge mainly because of Rhodes Scholarship bring those places mainstream attention.