Taking a guess that it's Juneteenth?
Memorial Day
Presidents' Day is a federal holiday that celebrates the birthdays of George Washington and Abraham Lincoln.
Juneteenth – also known as Freedom Day, Jubilee Day, Liberation Day, and Emancipation Day – is a holiday celebrating the emancipation of those who had been enslaved in the United States.
The Slavery Abolition Act 1833 us what helped end the slave trade.
They celebrate the fourth of july its a holiday where everyone celebrates the independence of america hope this awnser was helpful! :)
Abolitionism
Because Veteran's Day is a Federal holiday, EVERY US State celebrates Veteran's Day.
The end of slavery.
The holiday of Passover is when we celebrate how HaShem brought us out of slavery in Egypt.
The Emaciation Proclamation began the end of slavery but it was formally outlawed by the Thirteenth Amendment to the US Constitution.
spirituals
Abe Lincoln