Leander Hoover founded the Hoover Steel Ball Company in 1913. When World War I broke out in Europe soon afterward, Hoover quickly became the only source outside Germany to produce top-quality ball bearings, which made him a fortune. He built a large mansion on Washtenaw but died in 1918 soon after moving in. His mansion, converted long ago to corporate offices, remains an Ann Arbor landmark. The company also survived and grew to become the largest in the city by 1984. It continues today as Hoover Precision Products, Inc.