The chiffon cake was created by an insurance agent from Los Angeles named Harry Barker in 1927.  The chiffon cake was the first new type of cake to be developed in over 100 years.  To achieve a lighter consistency it uses oil instead of butter and, the key difference of the chiffon cake, it uses separated eggs where the whites are first beated with sugar instead of mixing the whole egg together.  These two steps give the cake a light airy nature, making it a happy medium between angel food cake and butter cakes.  Barker served his Chiffon cake at the Brown Derby restaurant and kept his recipe a secret.  Finally in 1947 he sold the recipe to General Mills who then published in in a 1948 issue of Better Homes and Gardens making it an instant success with home bakers.  Chiffon Cake was the poster recipe for the companies ad campaign to market their cake flour and vegetable oil.  With so much exposure and the fact it was a new type of cake chiffon cakes became increasingly popular and served at birthdays and most formal gatherings.  Almost any older cook book has at least one recipe for them.