The naturalist and explorer Alexander von Humboldt (1769-1859) achieved unparalleled fame in his own time. Today, however, he and his enormous legacy to American thought are virtually unknown. In The Humboldt Current, Aaron Sachs traces Humboldt's pervasive influence on American history through examining the work of four explorers--J. N. Reynolds, Clarence King, George Wallace, and John Muir--who embraced Humboldt's idea of a "chain of connection" uniting all peoples and all environments. A skillful blend of narrative and interpretation that also discusses Humboldt's influence on Emerson, Whitman, Thoreau, Melville, and Poe, The Humboldt Current offers a colorful, passionate, and superbly written reinterpretation of nineteenth-century American history.