Leonard C. Bailey patented the first "folding bed" on July 18, 1899. The metal bed frame was collapsible, folding mattress when closed for use as needed. The invention later became known as a "hide-a-bed."
In 1908, William Lawrence Murphy patented his "In-A-Dor" bed, which is still known as a "Murphy Bed." The space-saver folded into a wall-closet. Subsequent varieties became known as "library beds." Murphy beds are still in use today.
In 1931, Bernard Castro used $400 from his savings to open a shop in New York where he sold the "Castro Convertible." The beds found a customer based among Depression-era families living in cramped apartment spaces. Most sofa beds sold today evolved from Castro's designs.
The futon sofa bed became the answer for a sofa bed with a more contemporary style and design. It first appeared in the United States during the early 1980s, mimicking its Japanese predecessors. William Brouwer developed the first sofa style convertible frame for sale in the United States.