1841-1927
- Botanist and Harvard University Professor, the first director of Harvard's Arnold Arboretum, whoserved the institution for over 54 years. He was the author of the monumental works, The Silva of North America and The Manual of the Trees of North America.
- Sargent, as the nation's leading expert on trees, was the chairman of the National Forestry Commission to survey the timber reserves of the United States, recommend the creation of new reserves, and submit a permanent policy for governing them. Although Muir was not a formal member of the Commission, he accompanied it on several tours of forest areas.
- Sargent traveled with Muir on several excursions, including Alaska, the western forest reserves, the U.S. South, and about half of Muir's 1903-4 world tour.
- Sargent was a major campaigner with John Muir fighting against the flooding of Hetch Hetchy Valley in Yosemite National Park.
- Muir tells this anecdote, about a trip with Sargent to Grandfather Mountain, North Carolina, when Muir became enraptured by the spectacular view of autumn colors from the top of the mountain: "I couldn't hold in, and began to jump about and sing and glory in it all. Then I happened to look around and catch sight of Sargent, standing there as cool as a rock, with a half-amused look on his face at me, but never saying a word. 'Why don't you let yourself out at a sight like that' I asked. 'I don't wear my heart upon my sleeve,' he retorted. 'Who cares where you wear your little heart, man,' I cried. 'There you stand in the face of all Heaven come down to earth, like a critic of the universe, as if to say, 'Come, Nature, bring on the best you have. I'm from BOSTON!'"