The Emerson Brothers: A Fraternal Biography in Letters is a narrative and epistolary biography based upon the lifelong correspondence exchanged among the four Emerson brothers: Charles Chauncy, Edward Bliss, Ralph Waldo, and William Emerson, as well as Charles' 181 letters to his fiancee Elizabeth Hoar (one of the few extended series of courtship letters surviving from this period) and 86 letters from the brothers to their paternal aunt Mary Moody Emerson in which they discuss their moral and theological upbringing and views. Often composed as "round robin" exchanges among and between the brothers, the Emerson brothers' correspondence is the last great untapped body of personal writings remaining in manuscript from within the Emerson family. These letters illuminate aspects of Waldo's character and personal and intellectual development that, lacking access to the letters, even his most sympathetic biographers and critics have thus far failed to appreciate fully; reveal that all of the brothers were invigorated by their shared sense of origin as well as by a sense of duty to improve upon their ancestors' literary and intellectual work; shine new light on Waldo's debt to William for his first serious encounters with German Higher Criticism in the mid 1820s; present new evidence about the devastation Waldo felt at the death in 1831 of his first wife, a correction to Waldo's own sometimes under-recorded sense of grief at her passing; demonstrate that Waldo's desire for financial security for himself, his mother, and his brothers was at least as powerful a motivation behind his resignation from Boston's Second Church in 1832 as were Ellen's death and his reservations about the Lord's Supper; and mark Waldo's self-conscious and steady progress away from the forms of institutionalized religion toward the career of lecturer, essayist, poet, and social reformer which earned him his reputation as a principal architect of American culture.