How did the poet Ellery Channing inspire Henry David Thoreau's writing?

Henry Thoreau’s best friend when he was young was his brother John. The two taught school together, went on a lengthy boat trip together, and even fell in love with the same woman. (She turned them both down.) Tragically, John died unexpectedly in January 1842. Ralph Waldo Emerson was Thoreau’s mentor, but he was also fourteen years older than his younger disciple. Theirs was a different kind of friendship. When Transcendental poet Ellery Channing moved...

Henry Thoreau’s best friend when he was young was his brother John. The two taught school together, went on a lengthy boat trip together, and even fell in love with the same woman. (She turned them both down.) Tragically, John died unexpectedly in January 1842. Ralph Waldo Emerson was Thoreau’s mentor, but he was also fourteen years older than his younger disciple. Theirs was a different kind of friendship. When Transcendental poet Ellery Channing moved to Concord, Massachusetts in 1842, he became Thoreau’s walking companion and one of his good friends.

By 1845, Thoreau longed to dedicate himself to his writing. He especially wanted to write a book about the boat trip that he and John had taken, years before. He made his frustrations known in a letter to Channing, who was then working for the Tribune in New York. Channing wrote back to Thoreau on March 5, 1845:

I see nothing for you in this earth but that field which I once christened “Briars”; go upon that, build yourself a hut, & there begin the grand process of devouring yourself alive. I see no alternative, no other hope for you.”  [from The Correspondence of Henry D. Thoreau, Volume 1: 1834-1848. Edited by Robert N. Hudspeth. Princeton: Princeton University Press, 2013, p. 268.]

Thoreau took this recommendation to heart. He knew that Emerson had bought some woodland along the north shore of Walden Pond. Thoreau asked if he could live there, and Emerson agreed. On July 4, he moved into a small house he had built near a cove at Walden. In hindsight, it seems as though Ellery Channing had given Henry Thoreau just the inspiration and validation he needed to embark on this now-famous project.