Rally participants listen to an address by Frank Bear Killer of the Oglala Lakota tribe outside the state Capitol in Lincoln, Neb., in 2016 to mark Lincoln’s first Indigenous Peoples’ Day. At least 10 states now celebrate some version of Indigenous Peoples’ Day.

Rally participants listen to an address by Frank Bear Killer of the Oglala Lakota tribe outside the state Capitol in Lincoln, Neb., in 2016 to mark Lincoln’s first Indigenous Peoples’ Day. At least 10 states now celebrate some version of Indigenous Peoples’ Day.