Big Mac

The Big Mac is McDonald's' signature sandwich consisting of (as per its famous advertising jingle, introduced in 1974) "Two all beef patties, special sauce, lettuce, cheese, pickles, onions, on a sesame seed bun." It was developed in Uniontown, Pennsylvania by Jim Delligatti, one of Ray Kroc's earliest franchisees, in 1967. The Big Mac first debuted at Delligatti's restaurant at a selling price of 45 cents. It was created to compete with a similar Big Boy sandwich. It was introduced nationwide in 1968. It consists of two 1.6 oz (45.4 g) beef patties. The Big Mac's bun is separated into 3 layers.

It is unknown to most what the "special sauce" on a Big Mac actually is, though some think it is simply thousand island dressing. Big Mac Sauce is delivered to McDonald's restaurants in sealed canisters designed by Sealright, which are dispensed on burgers with tools that are similar to caulking guns.