Phillips, who was singing the American Indian Movement song that serves as a ceremony to send the spirits home, said he noticed tensions beginning to escalate when the teens and other apparent participants from the nearby March for Life rally began taunting the dispersing indigenous crowd.

A few people in the March for Life crowd began to chant “Build that wall, build that wall,” he said.

“It was getting ugly, and I was thinking: ‘I’ve got to find myself an exit out of this situation and finish my song at the Lincoln Memorial,’ ” Phillips recalled. “I started going that way, and that guy in the hat stood in my way and we were at an impasse. He just blocked my way and wouldn’t allow me to retreat.”

So, he kept drumming and singing, thinking about his wife, Shoshana, who died of bone marrow cancer nearly four years ago, and the various threats that face indigenous communities around the world, he said.