At Washington's National Cathedral, President Bush and four former presidents gathered to pay tribute, while at a Jewel-Osco store in Glendale Heights, about 100 customers and employees lit candles, one by one, observing a moment of silence.
Across the globe, thousands of ordinary citizens joined Americans in voicing sympathy and support. In Dublin, a small group of Illinoisans who had attended an ecumenical service of remembrance and healing broke into an emotional, a cappella version of the national anthem on the steps of St. Mary's Pro-Cathedral. When they finished, a crowd of Dubliners burst into cheers, shouting, "God bless America."
Chicago-area ceremonies gave some people their first real opportunity since the terrorist acts of three days earlier to express grief and demonstrate solidarity.
At perhaps the biggest local gathering, several thousand people of all descriptions jammed the Daley Center Plaza for a short, but emotional, observance highlighted by a stirring rendition of "God Bless America" by Melina Pyron of the Lyric Opera Center for American Artists.
Some in the audience dabbed at their eyes as a bell from the nearby First United Methodist Church at the Chicago Temple pealed in the background. Mayor Richard Daley and Gov. George Ryan and their wives hosted the event but did not speak.
"I think it was wonderful to come here to be with this great communion of people with the same hope for peace in our hearts," said Sue Ryan of Chicago, who attended with her husband. "It's really nice to see a gathering of people so solemn and yet so proud."
Several blocks away, a large crowd overflowed Pioneer Court on North Michigan Avenue for another memorial.
Lana Layne, one of those in the throng said, simply, "I'm here to feel with everyone else."
On the North Side, the green bell of the Midwest Buddhist Temple rang repeatedly before a small noontime service, while about 30 people filled the chairs and lined the walls of the chapel at the Pacific Garden Mission just south of the Loop.
"I prayed for understanding," said Billy Bailey, 40, who held a Bible under a tattooed arm. "I prayed for the people that were behind this thing, that God would forgive them."
In Lemont, a Hindu priest chanted a prayer in Sanskrit for the lives that were lost and dropped flower petals at the feet of a statue representing God.
At the Near North Side's Moody Bible Institute and at Benedictine University in Lisle, students and staff formed human chains.
Several hundred people, many in tears, gathered for a ceremony in the Lincoln Plaza at the Lake County Building in Waukegan. And hundreds more came together for 10 minutes of prayer and silence in the DuPage County administration building in Wheaton.
An untold number of smaller observances also took place.
At the Jewel-Osco in Glendale Heights, employees pulled packages of candles off the shelves for the vigil there. Gathering around the customer service counter, they observed a moment of silence and recited the Pledge of Allegiance and the Lord's Prayer. Some sobbed.
"It was important to have everyone together," said store manager Joe Pestillo.
Just before noon, Paul Sourounis, owner of Sante restaurant in Hoffman Estates, called his waitresses and hostesses together. In a semicircle they stood briefly in front of a television to watch the service in Washington.