Law & Order is in its twentieth season (as of 2009) and is tied with the western Gunsmoke as the longest running prime-time drama in US television history. The pilot episode, incredibly enough, was rejected by the executives over at the CBS television network back in 1988, but was later picked up by NBC and the rest, as they say, is history.

The success of the original Law & Order series spawned additional adaptions of the franchise, including Law & Order: Criminal Intent, and Law & Order: Special Victims Unit (which has gone on to be the most popular of the three shows). A third spin-off entitled Law & Order: Trial by Jury was canceled after just 13 episodes. It was the only series that detoured from the central theme of the original series by focusing almost entirely on the courtroom side of the justice system.

The combination of both the detective investigation side of the system along with the courtroom dramatics has proven to be an ongoing successful model for the series.

Shot in New York, Law & Order is known for its “local color” by often casting as guests true-to-life public figures such as New York City mayors Rudy Giuliani and Michael Bloomberg as well as attorney William Kunster, who have all appeared on the show, playing themselves.

Because of the longevity of the show there have been numerous character changes and none of the original six characters are still a part of the current episodes. There is a long list of great actors and actresses that have held leading roles throughout the many seasons. The list includes Chris Noth, who played Detective Mike Logan; Dann Florek, who played Captain Don Cragen (who now is a lead character in the spin-off Law & Order:  Special Victims Unit); and Steve Hill as D.A. Adam Schiff, who was apart of the cast from 1990 through 2000.

More recent stars include S. Epatha Merkerson as Lt. Anita Van Buren, who has continued to play the role since 1993. Then there was Jerry Orbach, who played the memorable, old school style cop, Detective Lennie Briscoe.

Along with numerous great lead characters the show has also presented some of the most recognizable names in television and movies as guest on the show, including Julia Roberts, James Earl Jones, Samuel L. Jackson, Chevy Chase,  Ludacris, the legendary Candice Bergen, as well as Ellen Pompeo and Kate Walsh (both of Grey’s Anatomy fame), just to name a few.