US Constitution in HTML5

About a year ago, I marked up the United States Constitution in HTML5 as a learning exercise. Fast forward a year, and I’m still not 100% certain I’ve gotten it correct. This document is troublesome in that it shares similar naming conventions with HTML5 tags, namely <article> and <section>. Does it make sense to have an Article contained with an <article> tag, or should it be in a <section>? In this case, I opted to stick with the document’s original naming conventions even though it may run counter to what’s currently suggested as a best practice on the matter.

How would you go about doing the markup for a pre-existing, historical document like this?