There was 18F which was a group within US Digital Services. But as mentioned they got DOGEd. They managed the USWDS (US Web Design System), which was making great efforts to create a unified design and accessibility framework for government websites. I was working pretty closely on a contract project until, well, shakes hands wildly all this. They were great people, great designers and really cared about what they were doing.

As for enforcement of adhering to 508 and a11y compliance, US digital projects were guided by executive order M-23-22, "Delivering a Digital-First Public Experience", but from what I can tell that is kind of up in the air at this point... we are following it until someone tells us otherwise, but I don't think it is being enforced anymore with any passion because of the current confusion.

For accessibility, sort of (as in they need to be accessible, but precisely what that means can be up to interpretation a bit and isn't necessarily well enforced), but regarding appearances, not really. Within an agency, maybe, cross-agency no.

They got doge'd