Hardee's, which had been co-owned with Denny's for a number of years by Trans World Corp (at one point also known as Advantica), was sold off to the west coast-based CKE Corp, owner of the Carl's Jr. chain. CKE attempted to rebrand the Hardee's as Carl's Jr, but local outcry prompted to them to keep the Hardee's name but use all other Carl's Jr branding such as the "smiling star" logo. They also kept a lot of Hardee's-specific items such as their breakfast menu with the made-from-scratch biscuit sandwiches.
Most of the Hardee's are located in the south and midwest. I can't hardly go anywhere around Mississippi without tripping over a Hardee's...they are about as ubiquitous as McDonalds is, around here.
There was a fairly good article in one of the restaurant industry trade magazine's a few years back (say 2001 or 2002) about some of the troubles CKE was having with the Hardee's brand (especially in areas where people initially objected to the "star Hardee's" concept, or at least the menu change). But in searching for that one, I found
this article from Portfolio magazine about the success CKE is having since instituting the "Star Hardee's" concept.