Soon after the success of the first film, 20th Century Fox paid Dean Devlin a large sum of money to write a script for a sequel. However, after completing the script, Devlin didn't turn in the script and instead gave the money back to the studio, as he felt the story didn't live up to the first film. It was only approximately 15 years later, that Devlin met up with Roland Emmerich to try again, having felt that they had "cracked" a story for a sequel.
(at around 3 mins) On the monument to The War of '96 seen in Washington, D.C. at the start of the film the name Russell Casse can be seen on a brick in the middle. Russell Casse was the name of Randy Quaid's character who sacrificed himself to destroy the ship approaching Area 51 in Independence Day (1996).
The movie is dedicated to actor Robert Loggia, who appears in both Independence Day (1996) and Independence Day: Resurgence, and passed away in 2015. The film's closing credits dedication reads: "In Memoriam: Robert Loggia".
The making of the movie had to shut down for about four days due to financing problems where the production ran out of money according to an interview with star Liam Hemsworth.
The movie had been given a $165 million production budget (not including marketing and distribution costs), $90 million more than its predecessor, Independence Day (1996), which had a $75 million budget 20 years earlier, and had a worldwide box-office take of $817.4 million, making it the highest grossing movie of 1996. "ID: Resurgence" however, only made $389 million worldwide, making it one of the biggest box office flops of 2016.
Robert Loggia: (at around 33 mins) As General William Grey. Loggia reprised his role from the original Independence Day (1996).