We don't know if Carver ever made peanut butter, but he certainly did not invent it.
The Aztecs mashed roasted peanuts into a paste, similar to peanut butter. Marcellus Gilmore Edson of Canada patented peanut paste made from roasted peanuts in 1884. Dr. John Harvey Kellogg patented a process for creating peanut butter from raw peanuts. Dr. Ambrose Straub of St. Louis, Missouri, patented a peanut-butter-making machine in 1903. Chemist Joseph Rosefield invented a process for making smooth peanut butter that kept the oil from separating in 1922.