Mildred Irene Clark, the youngest daughter of five children, was born on 30 January 1915 in Elkton, North Carolina. Her mother was Martha Darling Clark and her father, William James Clark, was a farmer and Methodist minister. After receiving her diploma from Baker Sanatorium Training School for Nurses in Lumberton, North Carolina, in 1936, Clark attended two six-month postgraduate courses. The first was a curriculum in pediatrics offered by the Babies Hospital in Wrightsville Sound, North Carolina. The second program at the Jewish Hospital in Philadelphia, Pennsylvania, prepared specialists in operating room administration and technique. Elizabeth Pearson, an instructor in Clark's training school, initially sparked her student's interest in the Army Nurse Corps. Pearson had served in the Corps in World War I and proudly demonstrated her status in the American Red Cross First Reserve after the war by always wearing her Red Cross pin. This mentor instilled in Clark the idea of patriotic service. Knowing that competition among applicants for the Army Nurse Corps was formidable, the determined Clark submitted her request for active duty one year in advance while still a student in the postgraduate course. Surprisingly, within fourteen days Clark received a request to report to Walter Reed General Hospital for a physical examination. Clark's application undoubtedly reflected her genuine love of country and convinced the gatekeepers that she was a prime candidate for the Army Nurse Corps.