Making use of his new wealth, in 1944 Johnson purchased a huge salt mine in Upper Michigan, whose tunnels extended over four kilometers below the surface. Much of Johnson's early success came from Aperture Fixtures, and with the company developing high-tech shower curtains for most branches of the United States military as well as the public, Johnson soon became a billionaire. Having his father's theories as the backbone, in 1943 he founded Aperture Fixtures, a shower curtain developer and manufacturer. In his youth, Cave Johnson became a successful business entrepreneur.
Cave's father was a farming professor at the institute of farming although he never farmed a day in his life.
