As of my knowledge cutoff in March 2023, Marion D. March was an influential astrologer, lecturer, and author known for her contributions to the field of astrology during the latter half of the 20th century. She co-authored a notable series of astrology books with Joan McEvers under the title "The Only Way to Learn Astrology," which is highly regarded in the astrological community for its detailed and accessible approach to teaching astrology to both beginners and advanced students. Marion D. March was recognized for her practical and psychological insights within the field and her dedication to teaching and professionalizing astrology. She also served in various capacities within astrological organizations and contributed to the greater understanding and acceptance of astrology as a serious study. Please note that the information provided is based on what was current as of early 2023 and there may have been developments since then.