B. Wayne Hughes, a sharecropper’s son who became a billionaire pioneering warehouses for Americans needing storage space, is buying thousands of houses to rent as more people find homeownership out of reach.

Hughes, 79, has purchased about 10,000 properties through his American Homes 4 Rent, making the Malibu, California-based firm the second-biggest owner of single-family rentals afterStephen Schwarzman’s Blackstone Group LP.