Juneteenth, the country's second day of independence, honors the end of slavery in the United States and came almost three years after the Emancipation Proclamation.
President Joe Biden signed a bill last year that officially recognizes Juneteenth as a federal holiday.
The federal holiday commemorates the day when over a quarter of a million enslaved Black people learned of their freedom after Maj. Gen. Gordon Granger and roughly 2,000 Union troops arrived at Galveston Bay, Texas on June 19, 1865.
Juneteenth is the first federal holiday established since Martin Luther King Jr. Day in 1983.
Juneteenth falls on Sunday, June 19, but will be observed in many places on Monday, June 20, this year.
Here's a look at what will be closed in observance of Juneteenth:
All nonessential federal government buildings and offices will be closed Monday.
Many public and private schools will be closed as well, but be sure to check your local school calendar.
U.S. stock markets will be closed Monday, including the New York Stock Exchange and Nasdaq.
USPS will be closed on June 20.
Most major restaurants along with retail, chain and grocery stores will remain open.
Companies such as Target, Best Buy and Nikehave made Juneteenth a holiday.