The first football helmet, or more known as a"head harness" was made in 1896. They were made out of leather.
Later on in around 1915, they started making helmets out of padded leather. They also added ear holes for better field communication.
Later on in around 1940, they started making plastic Riddell helmets.
In 1971 Riddell got a patent for "Energy absorbing and sizing means for helmets.
Finally in 1976 for a concern of safety, they added a chin strap on the helmets.