Fiberglass has multiple uses. It acts as an insulator, building material, and even boat hulls.
First, in 1870, John Player developed a process to mass-produce glass strands with seam jets used for insulation. By and large, this is arguably the first fiberglass.
Eventually, in 1880, Herman Hammesfahr patented weaving glass fibers to silk, making it durable and flame retardant.
Modern fiberglass is an accidental discovery. Corning Glass sold cookware. Product developer Dale Kleist was working to fuse glass pieces together. He thought the molten glass was not fusing correctly. To cool it down, he shot it with compressed creating a flood of thin glass fibers, modern fiberglass.
In 1935, Corning Glass started a co-development project with Owens-Illinois, another company working on fiberglass. The next year they merged, forming Corning-Owens, the company’s still current name.
By the late 1930s and early 1940s, they were spinning the fibers into cloth to reinforce laminates.
In 1936, DuPont’s Carlton Ellis patented polyester resin. Germany perfected combining it with fiberglass to make light and strong laminates. Eventually, during WWII, Allied spies stole the technology and brought it to the US. This material is the forerunner of modern laminates. Cars, boats, and even aircraft use light, strong laminates.