18 years ago, Independence Day (ID4 for short) was released. It was a science fiction disaster film about an alien invasion of Earth and starred a host of A-list actors such as Will Smith, Bill Pullman, Jeff Goldblum, Mary McDonnell, Judd Hirsch, Margaret Colin, Randy Quaid, Robert Loggia, James Rebhorn, Vivica A. Fox, and Harry Connick, Jr. The film narrative focuses on a disparate group of people who converge in the Nevada desert and, along with the rest of the human population, participate in a last-chance counterattack on July 4, the same date as the Independence Day holiday in the United States. It was directed by German director Roland Emmerich, who co-wrote the script with producer Dean Devlin. While promoting Stargate in Europe, Emmerich came up with the idea for the film when fielding a question about his own belief in the existence of alien life. He and Devlin decided to incorporate a large-scale attack when noticing that aliens in most invasion films travel long distances in outer space only to remain hidden when reaching Earth. Principal photography for the film began in July 1995 in New York City, and the film was officially completed on June 20, 1996.

(Film: ID4)

The film was scheduled for release on July 3, 1996, but due to its high level of anticipation, many cinemas began showing it on the evening of July 2, 1996, the same day the story of the film begins. The film's combined domestic and international box office gross is $816,969,268, which, at the time, was the second-highest worldwide gross of all time. It is currently the 42nd highest-grossing film of all time and was at the forefront of the large-scale disaster film and science fiction resurgences of the mid-to-late-1990s. It won the Academy Award for Best Visual Effects, and was also nominated for Best Sound Mixing.

Will Smith played Captain Steven Hiller, an assured U.S. Marine Corps F/A-18 pilot with VMFA-314. Devlin and Emmerich had always envisioned an African-American for the role, and specifically wanted Smith after seeing his performance in Six Degrees of Separation. Bill Pullman played Thomas J. Whitmore, the President of the United States and a former Persian Gulf War fighter pilot. To prepare for the role, Pullman read Bob Woodward's The Commanders and watched the documentary film The War Room. Jeff Goldblum played David Levinson, an MIT-educated computer expert, chess enthusiast, and environmentalist, working as a satellite technician in New York City, whilst Mary McDonnell played the First Lady Marilyn Whitmore, President Whitmore's wife. Judd Hirsch played Julius Levinson, David's father. The character was based on one of producer Dean Devlin's uncles.

Robert Loggia played General William Grey, a U.S. Marine Corps general who is the Chairman of the Joint Chiefs of Staff. Loggia modelled the character after generals of World War II, particularly George S. Patton. Randy Quaid played Russell Casse, a widowed, alcoholic crop duster and veteran Vietnam War pilot who claims to have been an alien abductee ten years prior to the film's events. Margaret Colin played Constance Spano, White House Communications Director and David's ex-wife. Vivica A. Fox played Jasmine Dubrow, a single mother, Steven's girlfriend and exotic dancer, and Harry Connick, Jr. played Captain Jimmy Wilder, Steve's best friend and fellow pilot. Connick took over the part for Matthew Perry, originally cast in the role.

The possibility of a sequel had long been discussed, and Devlin once stated the world's reaction to the September 11 attacks influenced him to strongly consider making a sequel to the film. Devlin began writing an outline for a script with Emmerich, but in May 2004, Emmerich said he and Devlin had attempted to "figure out a way how to continue the story", but that this ultimately did not work, and the pair abandoned the idea. In October 2009, Emmerich said he once again had plans for a sequel, and has since considered the idea of making two sequels to form a trilogy. On June 24, 2011, Devlin confirmed that he and Emmerich have found an idea for the sequels and have written a treatment for it, with both Emmerich and Devlin having the desire for Will Smith to return for the sequels. In October 2011, however, discussions for Smith returning were halted, due to Fox's refusal to provide the $50 million salary demanded by Smith for the two sequels. Emmerich, however, made assurances that the films would be shot back-to-back, regardless of Smith's involvement. In July 2012, Devlin reiterated that the Independence Day sequel is still in development, and the script currently takes place 16 years after the original film's events (matching up to real world time passed).

In March 2013, Emmerich stated that the titles of the new films would be ID Forever Part I and ID Forever Part II. The films will take place twenty years after the original, when reinforcements of the original alien race arrive at Earth after finally receiving a distress call. Bill Pullman has confirmed his participation, though Will Smith has not. The new films will focus on the next generation of heroes, including the stepson of Smith's character in the original film. In May 2013, Roland Emmerich and Dean Devlin mentioned that wormholes would be used as a plot device in ID Forever and added that they would like Jeff Goldblum to reprise his role from the original. The film was originally going to be released on July 3, 2015. In June 2013, Emmerich confirmed to the Daily News that Will Smith is not returning to the sequel. Later in June, it was officially confirmed that both Goldblum and Pullman would return in the sequel, and that a gay character would be prominently featured. On September 26, 2013, actor Michael B. Jordan was said to have been considered for a role in the film. On November 12, 2013, it was announced that the first sequel had been rescheduled for a July 1, 2016 release. On May 29, 2014, it was announced that the script for the first sequel written by Emmerich and Devlin would be rewritten by Carter Blanchard.