"Merry Christmas, Charlie Manson!" is the sixteenth episode in the second season of the American animated television series "South Park". The 29th episode of the series overall, it originally aired on Comedy Central in the United States on December 9, 1998. The episode was written by series co-creator Trey Parker, along with Nancy M. Pimental, and directed by Eric Stough.
Individuals in the United States were the first to have the opportunity to watch the airing of the 29th episode of South Park.
The statement says that the 29th episode originally aired in the United States (i.e. that was the first place it was aired, and therefore individuals residing in the United States at the time were the first to have the opportunity to watch it). This likely tricked the algorithm because it was unsure what it meant for someone to be in the United States as opposed to somewhere else.