Carnegie spent his last years as a philanthropist. From 1901 forward, public attention was turned from the shrewd business acumen which had enabled Carnegie to accumulate such a fortune, to the public-spirited way in which he devoted himself to utilizing it on philanthropic projects. He had written about his views on social subjects and the responsibilities of great wealth in "Triumphant Democracy" (1886) and "Gospel of Wealth" (1889). Carnegie bought Skibo Castle in Scotland, and made his home partly there and partly in his New York mansion located at 2 East 91st Street at Fifth Avenue. The building was completed in late 1902, and he lived there until his death in 1919. His wife Louise continued to live there until her death in 1946.