Answer:
To reinforce his main argument that slavery opposes the ideals of America.
Step-by-step explanation:
One of the objectives of Douglass's speech is to show how America behaves like a hypocrite. This is also expressed in this passage, as Douglass argues that of all countries in the world, America is the most hypocrite. His reasoning is that America claims to be the "land of the free" while at the same time allowing slavery. This shows that slavery is completely opposed to the ideals of America.