The first, Seton Animal Chronicles: Jacky the Bearcub, was inspired by Monarch, the Big Bear of Tallac, a novella published by Charles Scribner's Sons in 1904. It's about a... Oh, why not let Seton's images carry the story.
Jacky, a bear cub, is orphaned after a hunter shoots his mother in the brain.
He's adopted by the hunter, who takes delight in his antics.
Jacky's sold to a crazy rancher who keeps him in chains.
He grows into adulthood, escapes, and feasts on lamb.
Shepherds fear Jacky, who they refer to as Monarch.
The hunter who adopted Jacky/Monarch all those years ago fails to capture him.
A second attempt is successful. The bear ends his days in captivity at Golden Gate Park, "seeking forever Freedom's Blue, seeking and raging – raging and seeking – back and forth, forever – in vain."
Monarch – or Jacky, if you prefer – did exist; that's him above. Though Seton took some liberties with the story of his early life, the bear lived his final years in a concrete pit, just as the author describes.
Everything is happier in Seton Animal Chronicles: Jacky the Bearcub because the bear never grows up. His fun filled days are spent with sister Jill, a Native American boy named Lan, and Lan's Grandpa Rocky (best not to dwell upon the incident in which Rocky killed Jacky and Jill's mother).
That third animated Seton series? Well, it appears to have been a grab bag of Seton stories, including a retelling of Monarch, the Big Bear of Tallac. The animation, a touch more sophisticated, depicts the author communing with his cartoon pals.
An aside: Remember that Miami bookseller who was selling all those print on demand copies of Bannertail? Well, he's listed a POD copy of Monarch, the Big Bear of Tallac at US$145.95. "Perfect Condition", he claims. I recommend the 106-year-old first edition, which is readily available for less than US$20.