Banks are closed on the 4th of July to mark the anniversary of the Declaration of Independence when the United States declared our independence from Britain.
If you trade stocks, the US markets will also be closed on the 4th since it’s a federal holiday in the United States. Independence Day is a federal holiday, and almost all businesses will close (except for boat rentals) to observe the occasion. The majority of banks will be closed for the 4th as well as the Federal Reserve. In some cases, depending on the day the 4th falls on each year in might be the following day where the holiday is observed, but with 2022 it falls on a Monday so it is observed that same day.