The solemn tradition sees Indigenous people and supporters gather on Cole’s Hill in Plymouth during the Thanksgiving holiday to point out that many Native Americans do not celebrate the arrival of the Pilgrims and other European settlers on the fourth Thursday of November.

“We want to educate people so that they understand the stories we all learned in school about the first Thanksgiving are nothing but lies,” Kisha James, a member of the Aquinnah Wampanoag and Oglala Lakota tribes, told the Associated Press.

“Wampanoag and other Indigenous people have certainly not lived happily ever after since the arrival of the Pilgrims.

“To us, Thanksgiving is a day of mourning, because we remember the millions of our ancestors who were murdered by uninvited European colonists such as the Pilgrims. Today, we and many Indigenous people around the country say, ‘No Thanks, No Giving.’”

The National Day of Mourning has been organized by the United American Indians of New England every year since 1970.

The event will begin at midday Eastern Time at Cole’s Hill, just above from Plymouth Rock in the waterfront area where the Pilgrims are said to have first arrived on the shores.

The event will also be broadcast via YouTube, with the stream going live 11:45 a.m. ET.

The organizers said that the National Day of Mourning will aim to “shatter the untrue image of the Pilgrims” as well as the “unjust system based on racism, settler colonialism, sexism, homophobia and the profit-driven destruction of the Earth” that they brought into the country.

A number of Indigenous people are set to deliver speeches to mark the occasion and to discuss the “history and the struggles that are taking place throughout the Americas.”

Following the gathering at Cole’s Hill, there will be a march through the historic district of Plymouth.

“Thanksgiving Day is a reminder of the genocide of millions of Native people, the theft of Native lands and the erasure of Native cultures,” the event website added.

“Participants in National Day of Mourning honor Indigenous ancestors and Native resilience. It is a day of remembrance and spiritual connection, as well as a protest against the racism and oppression that Indigenous people continue to experience worldwide.”

The organizers also state that all those who will be attending the event in person must wear a mask as the COVID-19 pandemic has hit Indigenous communities “very hard.”