In what had long been celebrated every May 30 to honor America’s fallen soldiers, Memorial Day officially became a federal holiday in 1971, observed on the last Monday in May.

Businesses increasingly have chosen to stay open on the holiday, leading to what is now one of the biggest retail sales and travel weekends of the year.

Here’s what is open and closed this year on Memorial Day:

GOVERNMENT BUILDINGS

Government offices, post offices, courts and schools are closed.