Saturday morning, as their visits began to all three sites of the 9/11 attacks, President Joe Biden and First Lady Jill Biden joined a large crowd at the National September 11 Memorial in Lower Manhattan.
The event began with tolling bell, a moment of silence, and the names of the victims were read outloud.
Later, at the Flight 93 memorial in Shanksville, Pennsylvania, speeches were given by former President George W. Bush and Vice President Kamala Harris, and they took part in a wreath-laying ceremony.
President Biden did not deliver official remarks at any of the three sites, but the day before, in a speech commemorating the victims, he stressed national unity and honored those who risked their lives to rescue, recover and rebuild.
"We saw a national unity bend. We learned that unity is the one thing that must never break. Unity is what makes us who we are. America at its best. To me, that's the central lesson of September 11th."
Also, on Biden's orders, the FBI released on Saturday the first of what is expected to be a series of declassified documents detailing the FBI's investigation into the 9-11 attacks.
The document relates to logistical support given to two of the Saudi hijackers, but does not provide proof that senior officials in the Saudi government were involved in the plot, as some believe it was.
It details connections and witness testimony that led the FBI to suspect that Omar al-Bayoumi, purportedly a Saudi student in LA, was a Saudi intelligence agent.
The document says he provided "travel assistance, lodging and financing" to two of the hijackers.
Biden's order came after more than 16-hundred people affected by the attacks called for the release of the documents, asking the President not to visit Ground Zero unless he does so.
Kim Sung-min, Arirang News