Answer:
carte blanche
Explanation:
The meaning of carte blanche is total freedom to do what you want, or what you think is best. So, since he was so famous, they let him have complete control on how to design the mural.
Hope this helps!
It is in his tone when he speeks he reveals the setting
Grand Canyon is the proper noun
It made things worst because it made it harder for the slave to escape to freedom.