Answer:
s to shame the American people specifically the people of Rochester, NY that asked him, knowing that he is a former slave to give a speech on the day of celebration of the American Freedom.
Here are some cites:
“Fellow citizens, pardon me, and allow me to ask, why am I called upon to speak here today? What have I or those I represent to do with your national independence?” - Paragraph 1
I hope this helps =D have a good night!