First of all, I agree that all of us should dress modestly and with good sense when in the Lord’s house (all the time, for that matter!) That doesn’t have to mean long skirts or jumpers, however.
On the topic of headcoverings; the pertinent canon law in the 1917 code was not “in context about the United States”, but for the entire Church. Though some continue to debate its meaning, I think that the new Code is clear:
*Can. 6 §1. When this Code takes force, the following are abrogated:
1/ the Code of Canon Law promulgated in 1917*
Beyond that, a papal encylical from 1976,* Inter Insigniores*, which addressed why the Church cannot ordain women, discussed in detail the Church’s tradition with regard to women, the attitude Jesus had towards women, and the stance of the Apostles towards women. There is reference to “the prescriptions of St. Paul concerning women”, and this, specifically:
papalencyclicals.net/Paul06/p6interi.htm
The encyclical is pointed in delineating between these practices of “minor importance”, no longer the norm (standard), and more important traditions. The requirement for headcoverings was a changeable discipline, not immutable doctrine.
It seems to me that the very specific mention of the practice - in an arguably dismissive tone - in a papal encyclical, no less, gives weight to the opinions of those who believe that the practice was reflective of the times and not something by which we should be measuring one’s piety or obedience today.