It provides background information on the topic.
and It gives the main topic of the paper.
A. Purpose
I believe this is purpose because she is writing to argue that distributing medicine to rural parts of the world was worth doing.
The Jazz Age was a post-World War I movement in the 1920s from which jazz music and dance emerged. Although the era ended with the outset of the Great Depression in 1929, jazz has lived on in American popular culture.
