Complex sentence: Humboldt's name and fame were made by his travels Spanish America, particularly his publication of the "Political Essay on the Kingdom of New Spain" and his later image as the premier European scientist was a later development.
Split into simpler sentences: Humboldt's name and fame were made by his travels Spanish America, particularly his publication of the "Political Essay on the Kingdom of New Spain". His later image as the premier European scientist was a later development.