Synopsis
The poem describes a young man passing through a town bearing the banner "Excelsior" (translated from Latin as "ever higher", also loosely but more widely as "onward and upward"), ignoring all warnings, climbing higher until inevitably, "lifeless, but beautiful" he is found by the "faithful hound" half-buried in the snow, "still clasping in his hands of ice that banner with the strange device, Excelsior!"
Read more about this topic: Excelsior (Longfellow)