Question: What trail did the trail, of which Potter-Blocker was a collateral branch, replace?
Sentence (from "Prince Yasuhiko Asaka"): Son-in-law of Emperor Meiji and uncle by marriage of Emperor Hirohito, Prince Asaka was commander of Japanese forces in the final assault on Nanjing, then the capital city of Nationalist China, in December 1937.
Relevant evidence: No