Neither budged.
Video footage of the tense confrontation quickly went viral, stirring outrage across the political spectrum. The teens' church apologised Saturday, condemning the students' actions. By Sunday, conservative commenters on social media were saying it was the students who had been wronged.
The young man at the center of the video, who identified himself to The Enquirer as 11th-grader Nick Sandmann, said he and his classmates had been called "racists," "bigots" and worse, and he was "remaining motionless and calm" in hope that things would not "get out of hand."
The Native American elder said he was caught in the middle.
"When I took that drum and hit that first beat . . . it was a supplication to God," said Nathan Phillips, a member of the Omaha tribe and a Marine veteran. "Look at us, God, look at what is going on here; my America is being torn apart by racism, hatred, bigotry."
The incident, and the finger-pointing that followed, seemed to capture the worst of America at a moment of extreme political polarisation, as discourse once again gave way to tribalism, and people drew conclusions on social media before all the facts were known.
"Did I provoke that?"
The students, from Covington Catholic High School in Park Hills, Kentucky, had come to Washington to participate in Friday's March for Life, one of scores of school groups bused to the annual event.
The Native American activists were there for the Indigenous Peoples March.
So were the Hebrew Israelites, who believe African-Americans are God's chosen people and the real descendants of the Hebrews of the Bible.
"We were there to teach, to teach the truth of the Bible, to show them our real history," said Shar Yaqataz Banyamyan, one of five Hebrew Israelites on the National Mall that day.
The group has militant members and "a long, strange list of enemies" that includes whites, Jews, Asians, members of the LGBTQ community, abortion rights advocates and continental Africans, according to the Southern Poverty Law Center.
Banyamyan said he and those with him Friday believe in using blunt language, but not violence. A video he posted to social media shows them insulting other marchers.
"Where's your husband?" one Hebrew Israelite told a woman who had stopped to argue with the group. "Bring your husband. Let me speak to him."
At one point, the Hebrew Israelites began arguing with Native American activists, telling them the word "Indian" means "savage," according to the video.
While the two groups argued, some students laughed and mocked them, according to Banyamyan and another Hebrew Israelite, Ephraim Israel, who came from New York for the event.
As tension grew, the Hebrew Israelites started insulting the students.
"Tell them to come over in the lion's den instead of mocking from over there," Banyamyan can be heard saying in the video. "Y'all dirty-ass little crackers, your day is coming."
"They were sitting there, mocking me as I was trying to teach my brothers, so yes the attention turned to them," Israel told The Washington Post. "I explained to them, you want to build the wall for Mexicans and other indigenous people, but you've never seen a black or a Mexican shoot up a school."
Phillips said he and his fellow Native American activists also had issues with the students throughout the day.
"Before they got centered on the black Israelites, they would walk through and say things to each other, like, 'Oh, the Indians in my state are drunks or thieves,' " the 64-year-old said.
Phillips said he heard students shout, "Go back to Africa!"
Sandmann said in his statement that he "did not witness or hear any students chant 'build that wall' or anything hateful or racist at any time. Assertions to the contrary are simply false."
He said he and his classmates were shouting cheers they knew from school, with permission from their chaperones, "to drown out the hateful comments that were being shouted at us by the protesters."
A mob mentality
By 5 p.m., the light was fading on the National Mall and both marches had mostly petered out. A group of about 100 Covington students had gathered on the stairs of the Lincoln Memorial, where they had been told to meet before catching their buses home.
The Hebrew Israelites were still there and still insulting the students.
"You all are a bunch of Donald Trump incest babies," Israel said to them, according to the video, before asking whether there were any black students among them.
When a black Covington student came forward, Israel called him "Kanye West" and the N-word, the footage shows. At that point, the students began chanting and jumping and shouting. The songs culminated in one student stripping off his shirt and shouting as others cheered.
"The chants are commonly used at sporting events. They are all positive in nature," Sandmann said. "We would not have done that without obtaining permission from the adults in charge of our group."
Banyamyan said the Hebrew Israelites took the performance as a racist impersonation.
"They were mocking my ancestors in a chant, one of them was jumping up and down like a caveman," he said. "Did I provoke that?"
To Jessica Travis, a Florida attorney who was at the memorial with her mother, the students looked out of control.
"The kids really went into a mob mentality, honestly," she said, adding that she did not see chaperones trying to control the situation. Travis said she heard one student tell the Hebrew Israelites to "drink the Trump water."
Jon Stegenga, a photojournalist who drove to Washington on Friday from South Carolina to cover the Indigenous Peoples March, recalled hearing students say "build the wall," and "Trump 2020." He said it was around that time that Phillips intervened.
"He said, 'I wish I could say something to these people, to the whole crowd,' " Stegenga said in an interview Sunday.
Another member of the Indigenous Peoples March suggested that Phillips start singing, the photographer said. Phillips played a prayer song on a drum as he walked toward the students.
Some of the students began doing a "Tomahawk chop" and dancing, the video shows. Although Phillips said he found it offensive, he kept playing as he walked.
Most of the students moved out of his way, the video shows. But Sandmann stayed still.
When asked why he felt the need to walk into the group of students, Phillips said he was trying to reach the top of the memorial, where friends were standing. But Phillips also said he saw more than a teenage boy in front of him. He saw a long history of white oppression of Native Americans.
"Why I should go around him?" he asked. "I'm just thinking of 500 years of genocide in this country, what your people have done. You don't even see me as a human being."
Phillips said he blamed the students and the Hebrew Israelites for what happened.
"If it wasn't for those Israelites being there in the first place, this wouldn't have happened," he said. "And if it wasn't for the lack of responsibility from school chaperones, this wouldn't have happened either."
Sandmann, in his statement, said Phillips bore responsibility as well.
"He locked eyes with me and approached me, coming within inches of my face," the statement said. "I never interacted with this protester. I did not speak to him. I did not make any hand gestures or other aggressive moves. To be honest, I was startled and confused as to why he had approached me. We had already been yelled at by another group of protesters, and when the second group approached I was worried that a situation was getting out of control where adults were attempting to provoke teenagers."
School officials and the Catholic Diocese of Covington released a joint statement Saturday, condemning and apologising for the students' actions, but they had no additional comment Sunday.
"The matter is being investigated and we will take appropriate action, up to and including expulsion," the statement said.
Covington Mayor Joe Meyer posted an column on the town website Saturday, denouncing what had happened. "Let me - as Covington's mayor - be absolutely clear," he wrote. "No. The videos being shared across the nation do NOT represent the core beliefs and values of this City."
Nathaniel Dimof, a 27-year-old Florida activist, launched a parody page on Facebook called "Covington Catholic White Male Entitlement High School." He said he created the page, which featured photos of the boys at the march as well as Covington teachers and administrators, after the school took down the review section of its Facebook page and made private its Twitter account. Commenters immediately started trying to identify the students in the photos he posted.
Sandmann said he had received "death threats via social media, as well as hateful insults. One person threatened to harm me at school, and one person claims to live in my neighbourhood."
He said he was "mortified that so many people have come to believe something that did not happen - that students from my school were chanting or acting in a racist fashion toward African Americans or Native Americans."
Travis, who was in town to attend the Women's March before sightseeing, said the scene on Friday startled her and her mother.
"It was really depressing," she said, "to see we are even more divided than ever."