Lewis Baxter was born on September 20, 1894 in Superior, Wisconsin, United States, one of three sons of Francis William Schwellenbach, a machine operator of German descent, and Martha (Baxter) Schwellenbach. As a young boy he acquired from his father such a deep admiration for William Jennings Bryan that his playmates called him "Bryan, " a nickname that remained with him for years.
Even in booming Spokane his father never achieved financial success. He died when Lewis was fourteen, and the boy sold newspapers and worked on railroad construction and in the wheat fields to finance further education. He later recalled his poverty-stricken youth as a "nightmare. "