Although people have been roasting and grinding up peanuts for millennia, it wasn’t until the late 19th century that Marcus Gilmore Edson invented a way to make a paste by milling roasted peanuts. Various other inventors made substantial contributions to the development of peanut butter over the following few decades. In 1922, one Joseph Rosefield figured out how to homogenize peanut butter so that the oil didn’t separate, and his process led to the commercial success of such brands as Peter Pan (my personal favorite to this day) and Skippy. Jif didn’t come along until 1958, and don’t even get me started on GIF. I understand that peanut butter fans can be quite particular about their preferred formulation (homogenized or not, sweetened or not, smooth or chunky, etc.). Today, enjoy peanut butter in whatever form makes you happiest!