Did Madam C J Walker invent the hair relaxer?

No, Madam C. J. Walker did not invent hair relaxer and did not sell any products with chemical hair relaxers. She also did not invent the straightening comb. There were chemical hair relaxers being used and being sold before she founded the Mme. C. J. Walker Manufacturing Company in 1906. Hot combs were sold by Sears and Bloomingdales as early as 1890.
Madam Walker developed a line of hair care products for African American women and a system of hair and scalp care that she called "beauty culture." Like her contemporaries Elizabeth Arden, Helena Rubinstein and Annie Malone, she was a pioneer of the modern cosmetics and hair care industries.