Question: Melville D. Landon travelled to Russia with which Kentucky politician known as the "Lion of White Hall"?
Sentence (from "Cassius Marcellus Clay (politician)"): Cassius Marcellus Clay ( ; October 19, 1810 – July 22, 1903), nicknamed the "Lion of White Hall", was a Kentucky planter, politician, and emancipationist who worked for the abolition of slavery.
Relevant evidence: Yes