Gatsby amassed his wealth over a period of about three years. After returning from World War I, he was determined to achieve the American Dream, which he believed was synonymous with wealth and social status. He became involved in various business ventures, some of which were less than savory. This included bootlegging, which was a lucrative illegal trade during the Prohibition era. By the time he purchased his mansion in West Egg, he had built a considerable fortune that he used to throw extravagant parties in hopes of attracting Daisy Buchanan, the love of his life.