On September 13, 1990, the drama series Law & Order premieres on NBC; it will go on to become one of the longest-running primetime dramas in TV history and spawn several popular spin-offs. According to the now-famous Law & Order formula, the first half of the hour-long program, which is set in New York City, focuses on the police as they investigate a crime—often inspired by real-life news stories—while the second part of the show centers on the prosecution of those accused of that crime. Each episode opens with a narrator stating: “In the criminal justice system, the people are represented by two separate yet equally important groups: the police, who investigate crime, and the district attorneys, who prosecute the offenders. These are their stories.”

Law & Order‘s cast has changed continually throughout its run. Among the best-known characters are Homicide Detective Lennie Brisco, who was played by Jerry Orbach from 1994 to his death in 2004; Lt. Anita Van Buren, played by S. Epatha Merkerson since 1993; District Attorney Jack McCoy, portrayed by Sam Waterson since 1993; Detective Mike Logan, played by Chris Noth from 1990 to 1995 (he later reprised the character for the spin-off Law & Order: Criminal Intent); Detective Rey Curtis, played by Benjamin Bratt from 1995 to 1999; and Detective Ed Green, played by Jesse Martin from 1999 to 2008. The actresses Jill Hennessey, Carey Lowell and Angie Harmon each did a stint on Law & Order as assistant district attorneys. Fred Thompson, who was a U.S. Senator from Tennessee from 1994 to 2002, portrayed District Attorney Arthur Branch from 2002 to 2007. In 2008, Thompson launched an unsuccessful bid for the Republican nomination for U.S. president. Law & Order has also featured a long list of guest appearances by famous actors, including Julia Roberts, Samuel L. Jackson, Chevy Chase and Edie Falco. Law & Order's twentieth and final season ended on May 24, 2010.

On September 20, 1999, Law & Order: Special Victims Unit, starring Mariska Hargitay and Christopher Meloni as a pair of New York City detectives who investigate sex-related crimes, premiered. Law & Order: Criminal Intent followed in 2001. Law & Order: Trial by Jury debuted in 2005 and lasted for one season.

The Law & Order franchise was created by Dick Wolf, who was born in 1946 and began his television career as a writer for such shows as Miami Vice.