Who is U.S. Nurses from The Surrender Tree: Poems of Cuba's Struggle for Freedom and what is their importance?

The US Nurses are made up of many people from many different races and cultures. These women include Clara Barton, the famous Red Cross nurse, and Sioux nuns. The nurses come to help both the Cubans and the American soldiers. One of the nurses, Josefina Two Bears, makes a vow to take care of the camp orphans.