What parts do you need help with?
Answer:

Douglass advocated equal justice and rights, as well as citizenship, for blacks. He begins his speech by modestly apologizing for being nervous in front of the crowd and recognizes that he has come a long way since his escape from slavery.
Answer:
noun
Explanation:
A dictionary gives the definition of a word, but also its use/functions (like noun, verb, adjective, and so on).
'n' stands for 'noun', to save space. It doesn't save much into a single entry (usually found once or twice)... but if you multiply that by 60 000 or 80 000 words in the dictionary, that sums up to a large number of characters saved... which translate into pages.