O Pioneers! is Willa Cather’s successful fusion of two separate stories: “Alexandra” and “The White Mulberry Tree”. “Alexandra”, written in late 1911, began at the same point as O Pioneers! and continued through Part I and the dream that now appears at the end of Part III (Lewis, 1953, 83). After a transformative trip to the Southwest in the spring of 1912, Cather spent a few weeks at her childhood home in Red Cloud, Nebraska where, on the edge of a wheat field, she had the idea for the tragic story of star-crossed lovers that became “The White Mulberry Tree”. An epiphanic creative moment occurred, however, when she put these two stories side by side and realized they …
Moseley, Ann. "O Pioneers!". The Literary Encyclopedia. First published 26 April 2011; last revised 30 November -1.
[http://www.litencyc.com/php/sworks.php?rec=true&UID=22354, accessed 18 April 2015.]