It was how I swam at Highland Park High School just north of Chicago 69-70.
My father took me to the Tacoma Elks circa 1954. The Elks was all male and the indoor basement pool was decorated in a Greek style. All the swimmers were sans swimsuits. No one seemed to mind so neither did I. The wet sauna was all nude too. Men did carry towels.
We had to swim in the nude at Bennett High School in Buffalo and Cleveland Heights High School in Ohio.