Performers were hard at work early Monday morning practicing for the event, which featured floats decked out with hundreds of thousands of flowers, along with show horses, marching bands and celebrities.
The 129th Rose Parade theme was "Making a Difference." This year, every float showcased what is making a difference in their community.
Float preparations were underway for almost a year, and New Year's Eve was crunch time. Volunteers scrambled to put finishing touches on their floats before the judges rated each one. Then, the floral masterpieces were brought to Pasadena.
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Actor Gary Sinise grand marshalled the event. He was chosen because of his devotion to veterans' issues.
Sinise, who played Vietnam vet Lt. Dan Taylor in 1994's "Forrest Gump," said when he was chosen that he was happy to serve as grand marshal because of the vets he seeks to help.
"If shining a little spotlight on me on January first can shine a spotlight on them to help me make a difference in their lives, I am very, very grateful to do that," he said.
Veterans and family members of those killed in action appeared on some of the floats.
Fans filled up the parade route along Colorado Boulevard, many of them since Sunday night.
The parade route stretched 3.5 miles on and around Colorado Boulevard, where spectators camped in tents and slept in RVs to have a good seat to see the floats when they started to drift by at 8 a.m.
Pasadena Police Chief Phillip Sanchez said there were no known threats to the parade but that fan safety remained first priority and security was tight.
Later in the day and just a few blocks away was the 104th Rose Bowl, which this year was a College Football Playoff semifinal pitting Oklahoma against Georgia.
The Associated Press contributed to this report.