Delaware is set to be the first state to implement full-scale sports betting operations later today.

Three casinos will be launching their full-scale sports betting operations at 1:30pm local time on Tuesday 5 June. This historic moment marks the first implementation of legalised sports betting following the US Supreme Court’s decision to repeal PASPA.
https://www.gamblinginsider.com/news/5354/delaware-launches-full-scale-sports-betting-operations