"It's jam-packed out here," said Simeon Brown, 41, who brought his four children and four nephews up from Charleston, S.C., to watch the extravaganza.
Under a clear, blue sky and enjoying temperatures in the mid-50s, hundreds of thousands of people packed Broadway, standing 20 deep in areas. Many were so far back they could only see the giant balloons floating overhead.
Rain dampened Thanksgiving festivities in some other areas.
James Britton kept a tight grip on a steaming mug of cappuccino as drizzle dampened the Woodward Avenue parade route in Detroit and temperatures sat in the 40s.
"It's a necessity," Britton, 21, said of the cappuccino. "If it had been a little colder, I might have stayed home."
Detroit's damp chill didn't deter competitors in the Turkey Trot, a road race that preceded the parade. Matt Engelbrecht, 17, ran clad only in shorts and green-and-white body paint, the colors of his Lake Orion High School.
"If I'm going to do it, I'm going to do it," Engelbrecht said.
A different kind of spirit was at work in Iraq, where President Bush made a surprise Thanksgiving visit to American troops in Baghdad.
"You are defending the American people from danger and we are grateful," Bush told some 600 soldiers who were stunned and delighted by his appearance.
"I can't think of finer folks to have Thanksgiving dinner with than you all," the president told soldiers of the 1st Armored Division and the 82nd Airborne Division at an airport mess hall.
Mr. Bush said the least he could do was come by and thank the troops, and even served the soldiers their supper — dishing out mashed potatoes and turkey, reports CBS News Correspondent Lisa Barron.
Thanksgiving dinner also was a fitting observation of the holiday elsewhere.
At San Francisco's Glide Memorial United Methodist Church, 1,200 volunteers served 6,000 meals, starting with breakfast at 7 a.m.
"I almost was in shock today to see the number of people that are in their late years coming in, but it's very moving," said the Rev. Cecil Williams, whose church began serving the meals 28 years ago.
Illinois Gov. Rod Blagojevich visited a shelter for homeless families in Chicago to read a Thanksgiving tale and drop off books, hats, coats and gloves for children living there.
The children told him the moral of his tale was that Thanksgiving is about eating, sharing and watching football. The governor corrected them, saying the lesson was that "whether you're eating turkey, whether you're eating chicken or whether you're eating White Castle, you're all together."
While the balloons floating down Detroit's Woodward Avenue included Elmo, Johnny Appleseed and Captain Underpants, New York City's annual procession of helium-filled characters featured an enormous turkey, Charlie Brown, a 63-foot-high Big Bird and Kermit the Frog.
The extravagant parade down Broadway also delivered a little New York sass as gravel-voiced actor Harvey Fierstein appeared as his flamboyant "Hairspray" character, Edna Turnblad, with the "Edna" character dressed as Mrs. Santa Claus.
A traditional Mrs. Claus rode with Santa on his sleigh as part of the parade's grand finale.
The openly gay, three-time Tony Award winner mentioned his parade appearance in an op-ed piece about gay marriage in Wednesday's New York Times. But Macy's, the parade's sponsor, cautioned that the holiday event was not "a platform for political and social issues."