The U.S. Postal Service and financial markets are closed in recognition of Labor Day, which has been a federal holiday since 1894.
Labor Day -- the first Monday in September -- is dedicated to the social and economic achievements of American workers.
It's an annual, national tribute to the contributions workers have made to the strength, prosperity, and well-being of the country, according to the U.S. Department of Labor.
It's not exactly clear who gets credit for suggesting the holiday but in June 1894, Congress passed an act making the first Monday in September a legal holiday.
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It's one of 11 annual federal holidays, which means a lot of people have the day off.
Here's a look at what's open and what's closed Monday:
U.S. Postal Service: There will be no mail delivery or pickup.
Financial markets: The New York Stock Exchange and most financial institutions are closed.
Liquor stores: Pennsylvania state stores are closed. New Jersey liquor stores are privately owned and usually are open, depending on the proprietors.
Community: Most public libraries in Pennsylvania and New Jersey are closed, as are federal, state, county and municipal offices.
Department of Motor Vehicles: The Pennsylvania and New Jersey DMVs are closed.
Transportation: LANtaBus and LANtaVan services will not operate; Transbridge is running a normal Sunday schedule on Monday. Susquehanna Trailways is operating on a holiday schedule.
Email KJ Frantz at kjfrantz@lehighvalleylive.com. Follow lehighvalleylive.com on Twitter at @lehighvalley. Find lehighvalleylive.com on Facebook.