During his senior year, McPhee began teaching agricultural education at Pomona High School in Los Angeles County.
He continued pursuing education as a career before enlisting in the United States Navy as an ensign during the final months of World War I.
Julian returned to San Francisco and married Alma Doyle, with whom he would have six daughters: Helen, Bernadette, Jean, Claire, Carol, and Jule Ann.
[1] By increasing profitable agricultural programs at Cal Poly San Luis Obispo, McPhee not only saved the college from being closed by the state, but developed Cal Poly San Luis Obispo from a two-year technical school to a four-year college in the California State University (CSU) system.
Prior to McPhee's appointment, in 1930 due to crushing budget constraints, Cal Poly transitioned to an all-male institution as a cost savings measure, a policy which continued until 1956.