I am 15 and love the NFL. Can you guys tell me about some players from history that I should know about? (ie Barry Sanders, Walter Payton)

Like the title says, I would like to know about some players from history. I know a little about Walter Payton, Barry Sanders, and some older Steelers like Bradshaw, Mean Joe Greene, Swann, Stallworth, and Jack Lambert and Jack Ham, but that's about it. So, who are some players I should know about to consider myself at least mildly knowledgeable about the history of the league. Also, please write about tthe players you mention, don't just state their names. Thanks!