Nightingale selects small contingents of white women who she believes represent the "right caliber" of woman to be a nurse. This deeply impacts the evolution and professionalization of the field of nursing in the United States. While Nightingale formalizes nursing, she also thwarts the work of Black nurses like Mary Seacole (the first nurse practitioner) who is rejected by Nightingale when she asks for aid in the Crimean war.