The couple, who has been identified as Angela Nikolau and Ivan Beerkus, were seen holding a pro-peace banner at the very top of the spire.
Organizers say more than 3,100 events have been registered in all 50 states and several other countries, with more than 9 million people expected.
Leqaa Kordia, a 33-year-old from the West Bank who has lived in New Jersey since 2016, had been held in a U.S. immigration detention center in Texas since last March.
The two teens charged with attempting to carry out what officials described as an ISIS-inspired attack in New York considered other targets before the mayor's residence.
Two men who brought explosives to a protest outside New York City's mayoral mansion said they were inspired by the Islamic State extremist group, a court complaint said.
The violence came after the United States and Israel attacked Iran, killing its Supreme Leader Ayatollah Ali Khamenei.