Story highlights Colin Kaepernick received the Eason Monroe Courageous Advocate Award from the ACLU

Former NFL quarterback filed grievance against league in October, claiming collusion

(CNN) As Colin Kaepernick made his way to the podium, a surprised crowd broke into thunderous applause.

The former NFL quarterback was honored by the ACLU of Southern California at the Bill of Rights Dinner in Beverly Hills on Sunday, receiving the Eason Monroe Courageous Advocate Award.

"We all have an obligation no matter the risk, and regardless of reward, to stand up for our fellow men and women who are being oppressed with the understanding that human rights cannot be compromised," Kaepernick said.

According to CNN affiliate KABC , Kaepernick's attendance was not announced before the event.

The ex-San Francisco 49ers quarterback became a lightning rod in 2016 when he refused to stand during the National Anthem, protesting what he believes are racial injustices and ongoing police brutality in the US. He drew fierce criticism for refusing to stand but also inspired athletes -- from elementary schools to professional leagues -- to join his movement.

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