Short answers, pulled from the story.
Nickelodeon launched on the 1st of April 1979, as the first cable channel for children in the United States. Its inaugural program was Pinwheel, which had previously been the sole broadcast on the QUBE cable system in Columbus, Ohio, beginning the 1st of December 1977.
Nickelodeon launched without advertising because it was positioned as a children's channel free from commercial interruption. Advertising was introduced in January 1984, the same year the network underwent a major rebranding of its programming and image.
Nickelodeon is owned by Paramount Skydance, operating as the flagship property of Nickelodeon Group, a sub-division of the Paramount Media Networks division. The channel and its sister networks MTV and VH1 were sold to Viacom in 1985.
Nick Jr. launched on the 4th of January 1988, as a preschool morning programming block on Nickelodeon. It became the standalone Nick Jr. Channel on the 28th of September 2009, replacing the Noggin channel.
Since 2021, Nickelodeon has aired at least one live National Football League game per year, produced by CBS Sports. The broadcasts feature elements unique to the channel, including green slime in the end zone and SpongeBob SquarePants' face superimposed on goalpost netting. In 2024, Nickelodeon offered the first alternate broadcast of a Super Bowl with a SpongeBob SquarePants-themed simulcast of CBS coverage.
Nickelodeon Studios was a production attraction at the Universal Orlando Resort that opened on the 7th of June 1990, housing production for programs including Clarissa Explains It All, What Would You Do?, and All That. It closed on the 30th of April 2005, after Nickelodeon relocated its production facilities to New York City and Burbank, California.