Following fashion in the USA

Yes I have a beautiful dress code to office in Sri Lanka. That is the saree in Indian or Kandian style.  I was wearing both to office. But casually I was wearing trousers/ jeans with a tee or tunic.  Therefore it was very easy for me to wear jeans in USA. Most of the educated native USA girls (in Florida) from a good society are wearing nice jeans-longs or shorts. Very decent. But in the malls and supermarkets I noted several big made ----- american ladies are wearing very ugly pair of shorts with a tiny blouse that reveals their body parts. Even ----- pregnant women. Ugly to look at. I asked from my friend "why they are wearing that way to show their big tummy and big b-- and underwears" She explained me those girls and some guys think that dresses are too s--y. Pity. But it is the country of freedom.  So nobody ever criticize and I too better shut my mouth.  Am wearing jeans/skirts to work and outing in any season without any problem.  ( because i used to wear those in my country even in high temperature ) I wear Dresses to parties as I did in Sri Lanka.
So, to me.... nothing changed in dress code.

I am a fashion photographer. I see what local designers create. It is just as nice, artistic and innovative as in other countries and continents where I lived. However, average Joe buys clothes in department stores. Clothing there is all the same, no matter what chain is it. No matter even if you are shipping now or in nineties. Some people in the cities care what they are wearing, but vast majority seem not to know anything beyond sneakers, jeans and t-shirt. Europe, Asia and Africa appreciate fashion more. America most of all appreciates comfort. In East Africa men wear suits when they go to buy groceries. In America men wear sweaters and jeans for classic music concert.

I think it's impossible to put all Americans into one category any more than you can with any other people. I'm sure that many women would like to wear couture fashion, but it's very expensive.  Some American women like to be trendy, some like to dress in a more classic, sophisticated way, and some don't care or can't afford anything but the basics. Some women love fashion and spend a lot of money on it, but for others it's not as important as taking care of their children and home first.  It depends on their personal priorities. Education and financial circumstances probably play a big role in it as well.
Men like my father, used to wear suits and ties to work every day, but then fashion became more casual and comfortable.  I think many people decided it was time that people were judged by the kind of person they are and the quality of their work, rather than by what they are wearing. I always wore suits and dresses to work, or nice pants, blouses, and jackets because it was more professional.
If someone goes to an opera, they wear evening clothes. If they go to a rock concert, they wear whatever they find comfortable. 
I see photos of people from all over the world and they are all wearing jeans and t-shirts, too. It's time we put stereotypes aside and start judging people for who they are instead of what country they come from or what clothes they are wearing.

I would say that in general, Americans are much more casual dressers than Europeans, for example. Women are not always made up with their hair done when they leave the house to run errands, like they would be for work. While there's no 'one way' to dress, people in cities seem to dress up a bit more than those in more rural areas or states with fewer shopping choices.

Expect to find baggier clothing on people over here. Since I returned from Europe, I went back to wearing wider straight leg jeans instead of skinny leg jeans, and also more casual shoes. I think you would find quite a few people wearing jeans, sometimes even at work, depending on the type of job they have. And as another poster noted, there are a lot of people who just don't know how to dress properly to leave their houses.

Although fashions are arriving here more quickly from Europe for example because of supply chains being faster and the internet being a bit influence, department stores have different merchandise in different locations, and so what a person finds at Macy's in New York is much different than what they will find in a smaller shop in the Midwest. In larger cities, there are H&M and Zara shops, and now some Uniqlo, just to name some more globally-oriented stores.

Prices vary a lot. Of course, the sky can be the limit for spending, and there are high-end boutiques that offer expensive looks and high quality. The global brands listed above and many American stores like Target also have less expensive options and department stores usually offer a range of prices. One should be aware that 'outlet malls' don't always have better prices than regular stores' sale prices, but they can still be good places to shop.

I grew up in rural and small town Corsica in the 70s. Depending on the weather, you wear short/t-shirt in the summer, jeans/shirt/boots in the winter. Depending also on what you're doing, we were dressing up for weddings, funerals or other official events. But most of the time it was practical or casual.

I didn't change much since I moved here. I wear jeans, polo shirt and either steel toe boots or a pair of sneakers at work. The weather in southern California allows me to wear t-shirts most of the time when I'm not at work. The only time I would wear a suit is again at weddings, funerals or also at the yearly company's Christmas party.

Living on a 2 acres mountain ranch, there's a lot of outdoors work to do, every weekends and sometimes on days off. Urban people or people living close to the coast tend do dress up a lot more often. So of course, depending on where you live and what you do, you will dress differently. There are pretty much the all spectrum of dress code in the US but I notice that there are more outdoors people here. By experience, expats from Europe almost all the time come from big European cities and see a lot more difference between Europe and the US because of this. But Europe has a lot of rural places too where people don't especially care about fashion.