Final answer:
In the late 1800s, nursing roles were filled by women, who were both professional nurses and volunteers from various social classes, with a notable expansion of women in medicine during World War I.
Step-by-step explanation:
In the late 1800s, nurses were primarily women, including well-trained professional nurses and volunteer nurses from the elite and middle classes. During World War I, opportunities for women in medicine expanded significantly. Women not only served as nurses close to the front lines but also engaged in other medical tasks such as driving ambulances and working in x-ray units.
The war effort saw a mix of experienced professional nurses and volunteer nurses who were crucial in providing medical care on both the home front and on the battlefield. In addition, a small number of female doctors gained a reputation for their work, highlighting women's evolving role in the medical field.