In January 1863, Fremont, then a Major-General in the Union Army, sold Rancho Las Mariposas with its mines and infrastructure to Morris Ketchum, a New York City banker, who formed a public corporation, the Mariposa Company, and sold stock. In 1863, Frederick Law Olmsted, later the renowned American landscape architect, came from New York to Rancho Mariposa as superintendent for the Mariposa Company. Olmsted was not a mining expert. Investments were made in stamp mills, tunnels, shafts, and the other infrastructure related to the mining towns. By 1865, the Mariposa Company was bankrupt, Olmsted returned to New York, and the land and mines were sold at a sheriff's sale.
