Courtesy wiki:
AMC is a cable television network that primarily airs movies. The letters originally stood for American Movie Classics. However, since 2003, the full name has been deemphasized (as is the case for TLC, and formerly TNN) as a result of a major shift in programming. AMC is owned by Rainbow Media Holdings, LLC, a subsidiary of Cablevision Systems Corporation, and signed on October 1, 1984.
AMC was originally a premium cable channel that aired classic movies during the afternoons and early evenings, largely pre-1950s, in a commercial-free, generally unedited format. It was not uncommon for the channel to host a Marx Brothers marathon, or show such classics as the original Phantom of the Opera. In the early 1990's, the channel shifted to a 24-hours-a-day, seven-days-a-week format.
The network has since dramatically changed its programming, shifting from premium to basic cable, emphasizing more recent movies, adding a new logo, with a lowercase a (seen above at right) and using a new slogan: "TV For Movie People." With competitors such as Turner Classic Movies and Fox Movie Channel, AMC changed its format from a classic movie network to a broader movie network, airing movies from the 1970's onwards.
The commercial-free format has also been abandoned. AMC airs fewer classic movies than they did years ago.