Question: Jonathan Clark is the older brother to a fellow soldier who was what? 
Sentence (from "John Schnitzer"): Sergeant John P. Schnitzer (1854 – October 26, 1904) was an American soldier and wagoner in the U.S. Army who served with both the 23rd U.S. Infantry and 6th U.S. Cavalry in the New Mexico Territory during the Apache Wars.
Relevant evidence: No