A Scottish-American businessman, a major and widely respected philanthropist, and the founder of the Carnegie Steel Company which later became U.S. Steel. He is known for having built one of the most powerful and influential corporations in United States history, and, later in his life, giving away most of his riches to fund the establishment of many libraries, schools, and universities worldwide. Carnegie first invested in railroads, railroad sleeping cars, as well as bridges and oil derricks. But steel was where he found his fortune. His book, The Gospel of Wealth, argued that the wealthy had an obligation to give something back to society. A widow of an army captain, Jackson became angered at what she considered the unfair treatment of Native Americans at the hands of US government agents. She became an activist and muckraker who started investigating and publicizing the agents' wrongdoing, circulating petitions, raising money, and writing letters to the New York Times on behalf of Indians. She also started writing a book condemning the government's Indian policy and the history of broken treaties. Her book, A Century of Dishonor, called for change from the contemptible, selfish policy to treatment characterized by humanity and justice, was published in 1881. Jackson then sent a copy to every member of Congress, but, to her disappointment, the book had little impact. She later led protests against the 1890 Dawes Severalty Act.