Former San Francisco 49ers quarterback Colin Kaepernick made a surprise appearance at the Alcatraz Indigenous People's Sunrise Gathering on Thursday, The San Francisco Chronicle reported.

A tradition in California since 1975, the annual dawn festivities, also known as Unthanksgiving Day, commemorate the occupation of Alcatraz by American Indians from November 1969 to June 1971, Newsweek reported. During that time, 89 American Indian activists and leaders occupied the island and former penitentiary and demanded it be turned into an Indian cultural center and school.

Kaepernick, who remains an unsigned free agent, spoke to the thousands gathered on the island, the Chronicle reported. His words evoked cheers and applause.

“Our fight is the same fight,” Kaepernick told the crowd, in a message he also posted on Twitter. “We’re all fighting for our justice, for our freedom. And realizing that we are all in this fight together makes us all the more powerful.”

Kaepernick has been criticized by President Donald Trump for refusing to stand during the national anthem as a protest against racism in the U.S.