This paper explores the origins of the great fortunes of the Gilded Age. It relies on two lists of millionaires published in 1892 and 1902, similar to the Forbes magazine list of the 400 richest Americans. Manufacturing, as might be expected, was the most important source of Gilded Age fortunes. Many of the millionaires, moreover, won their fortunes by exploiting the latest technology: Alfred D. Chandler's "continuous-flow production." A more surprising finding is that wholesale and retail trade, real estate, and finance together produced more millionaires than manufacturing. Real estate and finance, moreover, were by far the most important secondary and tertiary sources of Gilded Age fortunes: entrepreneurs started in many sectors, but then expanded their fortunes mainly through investments in real estate and financial assets. Inheritance was also important, especially in older regions. The observations, moreover, come before and after the Crisis of 1893, one of the most severe financial crises of the nineteenth century. The data reveal a high degree of survival among the great fortunes, and perhaps most surprising, a high degree of survival for fortunes based on real estate.