I make a pact with you, Walt Whitman -
I have detested you long enough.
I come to you as a grown child
Who has had a pig-headed father;
I am old enough now to make friends.
It was you that broke the new wood,
By referring to himself as a grown child, Pound is not only acknowledging the fact that he has grown up and changed his views, but also the fact that he views Whitman as a sort of father figure.