USA

"The powwow is a celebration of the indigenous American Indian culture. People from diverse tribes and nations gather together on this day for a feast for the eyes with traditional dances, songs, and rituals to honor the traditions and culture of their ancestors."

This is a day for honouring and mourning the U.S. military personnel who died while serving in the United States Armed Forces. (Wikipedia)

This day commemorates the adoption of the flag of the United States on June 14, 1777. (Wikipedia)

This day commemorates the end of slavery. Its name is a portmanteau of "June" and "nineteenth", as it is celebrated on the anniversary of June 19, 1865, when as the American Civil War was ending, Major General Gordon Granger ordered the final enforcement of the Emancipation Proclamation in Texas. (Wikipedia)

Indigenous Peoples' Day is a holiday in the United States that celebrates and honors indigenous American peoples and commemorates their histories and cultures. It is celebrated across the United States on the second Monday in October, as a counter-celebration of the same day's Columbus Day. (Wikipedia)