Instructions
Look at the rays in the center of the glass work. On Old Pink Hobnail (or English Hobnail) glass there are uneven rays in the center of the glass. On the Miss America glass these rays are of even lengths.
Check if the glass is machine molded or hand molded. Depression-era glass was machine molded with intricate designs, but English Hobnail was still handmade. Look closely at the design to identify this.
Look at the quality of the glass. English Hobnail and another glass called "Radiance" were two glasses made in the Depression era that used higher-quality glass. This means that it will be thicker and more robust.
Check the production colors of the glass. Each glass company has its own colors.
Check your glass with a glass expert or get a reference book such as "Westmoreland Glass--The Popular Years 1940-1985" by Lorraine Kovar.