Hardee's are generally found in the Midwest, Southeast, and Mid-Atlantic, while Carl's Jr. dominates the West Coast and Southwest. The two chains have essentially identical menus and branding, but there are still two states where you can find both restaurants.

In 1964, Carl Karcher, founder of Carl’s Jr., was doing so well that he incorporated his businesses into a single entity, CKE Restaurants. CKE Restaurants purchased Hardee’s in 1997, and Carl's Jr. and Hardee's then exchanged recipes and designs, explaining their similarities.

Hardee’s and Carl’s Jr. enjoyed parallel success before joining forces, and they generally keep separate in a display of solidarity. The two burger joints split the country into regions and overlap only in Oklahoma and Wyoming.