Notes on verification

Multiple independent, reputable sources (Wikipedia, Bowdoin College, Naval History and Heritage Command, Dartmouth Library) confirm 1856 as Peary's birth year; minor day discrepancy in one source does not affect the year. [cascade flags: wikipedia_dropped_other_sources_exist | tier=silver indep_score=0.95 clusters=3 claim_tier=everyday | kind=empirical eligibility=high]