Final answer:
The Macy's Thanksgiving Day Parade is the event in which someone's balloon was added to the festivities.
Step-by-step explanation:
The event in which someone's balloon was added to the festivities was the Macy's Thanksgiving Day Parade. This iconic parade, held annually in New York City on Thanksgiving Day, features giant helium balloons that are part of the celebration. People get to see their favorite characters and objects come to life as giant balloons floating through the parade route.
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