Carnegie started work as a telegrapher, and by the 1860s had investments in railroads, railroad sleeping cars, bridges, and oil derricks. He led the expansion of the American steel industry. After selling Carnegie Steel, he surpassed John D. Rockefeller as the richest American for the next several years. He became a leading philanthropist in the United States and in the British Empire. During the last 18 years of his life, he gave away almost 90 percent of his fortune to charities, foundations, and universities. His 1889 article proclaiming "The Gospel of Wealth" called on the rich to use their wealth to improve society, and stimulated a wave of philanthropy.