Florence Nightingale
Starting in the early 1860s, Nightingale took an interest in health issues in British India. She wrote early essays lamenting the state of Indian sanitation. In 1878, she wrote an influential essay for The Nineteenth Century called "The People of India," which called the government of India to account for its failure to seriously take on the suffering and death in the Madras Famine of 1876-1878.
See an extract from "The People of India" here