What is the passage mainly about?

Andrew Carnegie was born in Dunermline, Scotland, on November 25, 1855. The son of a weaver, he came with his family to the United States in 1848 and settled in Allegheny, Pennsylvania. At age thirteen, Carnegie went to work as a bobbin boy in a cotton mill. He then moved rapidly through a succession of jobs with Western Union and the Pennsylvania Railroad. In 1865, he resigned to establish his own business enterprises and eventually organized the Carnegie Steel Company, which launched the steel industry in Pittsburgh. At age sixty-five, he sold the company to J. P. Morgan for $ 480 million and devoted the rest of his life to his philanthropic activities and writing, including his autobiography.
     Many persons of wealth have contributed to charity, but Carnegie was perhaps the first to state publicly that the rich have a moral obligation to give away their fortunes. In 1889 he wrote The Gospel of Wealth, in which he asserted that all personal wealth beyond that required to supply the needs of one’s family should be regarded as a trust fund to be administered for the benefit of the community. During his lifetime, Carnegie gave away over $ 350 million. He died in Lenox, Massachusetts, on August 11,1919.