In a “memo” probably entered in 1933 Ives offered his most extended explanation of the Concord Sonata sources and their chronology (Memos, pp. 79–83). The time frame he presents at the outset of his remarks, “mostly between 1911 and 1915 (when it was finished),” agrees with the dates he offers on the final amended list of works he compiled about 1949 (Memos, pp. 79 and 162). In the 1933 memo Ives also cites specific completion dates for “Hawthorne” (October 12, 1911), “The Alcotts” (1913), and “Thoreau” (1915) (Memos, pp. 81–82).
Two years later in a written response to John Kirkpatrick's questions, Ives offers a specific completion date for “Emerson” (“summer of 1912”), a revised year for “The Alcotts” (1915), and confirms the dates offered in 1933 for “Hawthorne” and “Thoreau” (Memos, p. 202). In a “second sketch” for this letter, Ives drafted, but did not send, the following recollection: “Shortly after 1911, at Pell's, I got the idea of a Concord sonata.” Also in this letter Ives gives a 1919 date for his Essays Before a Sonata, a 1911 date for the Emerson Overture (presumably the “uncompleted score for orchestra” upon which the Four Transcriptions from “Emerson” were based), and assigns a time frame for the first transcription “sometime after 1915 and before 1918.”
According to Ives's account, several works, nearly all eventually abandoned, featured material that would find their way into the Concord Sonata after 1911. One of these was an “Alcott Overture, 1904, with a theme and some passages used in the sonata” (Memos, p. 163).