What is associated with: a horse born december 31 1998 became a yearling on this date?

Based on the clue 'a horizontal blade on the back of a car or a back ...', what is the answer? Based on the clue 'a horn named olifant which was sounded too late to...', what is the answer? Based on the clue 'a horse a horse my kingdom for a horse', what is the answer? Based on the clue 'a horse a horse my kingdom for a horse', what is the answer? Based on the clue 'a horse has got to learn to stand on his own four ...', what is the answer? Based on the clue 'a horse is a horse of course of course and no one ...', what is the answer? What is associated with: a horse named comanche survived this mans june 1876 last stand? Based on the clue 'a horse or a person impatient at being held back i...', what is the answer?