Thomas Jefferson and John Adams both died on July 4, 1826 - the fiftieth anniversary of the Declaration of Independence's ratification. This has since become common knowledge, but at the time, Sherman Edwards and Peter Stone didn't include the fact in the play because they believed no one would believe it.
In the song Is Anybody There, sung by John Adams, the lyric "Yet, through all the gloom, I see the rays of ravishing light and glory" were from a letter by the real-life Adams to wife Abigail the day after the Declaration was adopted.
According to the writer/director's commentary, John Adams' actual quote following Franklin's urging to remove the slavery clause from the declaration was "If we give in on this issue, there WILL be trouble 100 years hence." The commentary stated that the quote was NOT used because it sounded too much like hindsight. Adams' forward looking prediction missed the first battle of the Civil War by only 15 years.
The final shot required the camera to pull back to show the entire Congressional chamber. However, there was not enough room on the set for the camera truck to pull back far enough. Since the sound stages being used were slated to be demolished after production ended, and this was the final shot being done, a large hole was made in the wall - with the camera truck protruding outdoors after pulling all the way back. As it turned out, the sound stages were never demolished and the wall was rebuilt.
All of the exchanges between John Adams and Abigail Adams are based on the real letters they wrote to each other while John was away. He called her his "dearest friend" and their letters ended with "Til then".
John Adams was portrayed by actor William Daniels, who later starred in the television show St. Elsewhere (1982) in which his character, Dr. Mark Craig, was a supposed descendant of John Adams. "St. Elsewhere" was filled with references to 1776 (1972) and quotes from the movie. During one "St. Elsewhere" episode, filmed in Philadelphia, Dr. Craig declares that "it's hot as hell in Philadelphia" and that he is "obnoxious and disliked", quoting his character from this film and also comparing Dr. Craig to John Adams by inference.
On the laserdisc commentary, director Peter H. Hunt says that originally he had not planned to cast Howard Da Silva as Benjamin Franklin in the film version, because of how difficult the actor had been during the Broadway run of the musical. However, he relented and let Da Silva reprise his stage role in the film when the actor promised to cooperate and begged to play Ben Franklin in the movie as a legacy to his grandchildren.
William Daniels, who portrays John Adams, also portrayed John Quincy Adams (John & Abigail Adams' oldest son and sixth President of the United States) in the mini series The Adams Chronicles (1976), Samuel Adams (John Adams' second cousin and also a signer of the Declaration of Independence) in the TV movie The Bastard (1978) and John Adams again in the TV movie The Rebels (1979).
Many of the outdoor shots were filmed at what is now the Warner Ranch just north of the main studio. The water fountain seen during the number with Benjamin Franklin, John Adams, and Richard Henry Lee is probably best known to television viewers as the fountain seen at the beginning of the TV show Friends (1994). The fountain still exists directly across the street from the house facades used in Bewitched (1964), and I Dream of Jeannie (1965). Most of the other colonial sets were destroyed by a devastating fire in the mid-70s.
Many of the characters' lines were actual quotes by these historic men, including Hancock's justification of his own signature and Franklin's: "Those who would forfeit liberty to obtain a little temporary safety..." as well as his saying, "We must all hang together, or assuredly we shall all hang separately."
The final scene shows the members of Congress being called individually to come forward in order to sign the Declaration of Independence while the camera trucks back, or zooms out. The characters' final positions are an approximation of John Trumbull's famous painting, The Declaration of Independence. The actual painting shows the congressional chamber from the front behind Hancock's desk while the scene in the movie is from the rear of the chamber, and therefore the characters appear reversed with the five members of Congress who were assigned to the committee to write the Declaration on the right of the desk as opposed to the left. Far fewer of the actual number of delegates, who were in Congress, are represented in the movie, but the resemblance to the painting is unmistakable including the delegate sitting with one leg crossed over another.
Charles Thomson served as the Secretary of the Continental Congress throughout its entire existence up until its disbanding in 1789. He was not offered a post in the new government which had been created by the ratification of the U.S. Constitution. He died in 1824 at the age of 94, and was a close friend of Thomas Jefferson until his death.
Charles Carroll of Carrollton was the only Catholic signer of the Declaration of Independence and the last signer to die, dying in 1832 at the age of 95. His cousin John Carroll was a Jesuit priest and the first Catholic bishop in the United States, becoming the Archbishop of Baltimore in 1790.
Director Peter H. Hunt and writer Peter Stone claim in the DVD commentary that President Richard Nixon was given a private screening of the movie before its release in 1972 by his friend, producer Jack L. Warner. The claim further goes on that the song "Cool, Considerate Men" offended Nixon (he thought that audiences would take it as a criticism of his presidency, even though the film was set two centuries earlier), so Warner removed it at Nixon's request. However, the documents from the Nixon Library (which lists all the movies viewed at the White House at the time) shows that "1776" was never previewed there. However, the documents do show that the Nixon family was given a performance of the stage play of "1776" at the White House on February 22, 1970, and this may be the cause of the confusion of about a private screening of the film. As Jack Warner was not in attendance for the 1970 performance, it remains an open question as to how much of the story behind Warner's cutting of the song is true. In any case, the song was restored on the deluxe wide screen presentation laserdisc and later was included on the restored director's cut DVD.
During the filming of Piddle, Twiddle, and Resolve, William Daniels sucked on ice cubes so as not to give away the fact that the night was freezing cold, rather than a humid summer evening in Philadelphia.
Ron Holgate, who portrayed Richard Henry Lee (VA), did all of his own riding - except for the trick mount at the end - in scene/song "The Lees of Old Virginia," despite the fact that he had never been on a horse before.
The song The Egg was written very late into the writing process for the Broadway show. So late, in fact, that promotional material had already been printed and it was upon seeing a poster depicting an eaglet coming out of a British eggshell and holding an American flag that Sherman Edwards came up with the song.
Of all the actors in this movie, only William Daniels and Ken Howard play future presidents of the United States - John Adams and Thomas Jefferson. Both actors were, in fact, also future presidents of the Screen Actors Guild. William Daniels was elected in 1999 for one term, and Ken Howard was elected in 2009 for two terms, mirroring their characters in this movie, John Adams was elected for one term, and Thomas Jefferson for two terms.
Although Thomas Jefferson (portrayed by Ken Howard), says, during the debate on the slavery clause of the Declaration of Independence, tells John Dickinson (portrayed by Donald Madden) that he has already resolved to free his own slaves, but he never did that during his lifetime, although arguably he did free some of his slaves after his death, or gave the discretion to his surviving daughter.
Although the Cool, Cool Considerate Men number was cut from the original film release as a favor to Richard Nixon by Jack L. Warner, the cut footage was not destroyed like Warner had done before in similar past circumstances since he was no longer a studio head. For that reason only, the excised segment was found and could be restored to the laserdisc and DVD. Nixon asked the writer Sherman Edwards to cut it out after seeing the play at the White House, but the author steadfastly refused.
The original Broadway production of the musical "1776" opened at the 46th Street Theater on March 16, 1969 and ran for 1217 performances. William Daniels (portraying John Adams (MA)), Howard Da Silva (portraying Dr. Benjamin Franklin (PA)), Ken Howard (portraying Thomas Jefferson (VA)), Roy Poole (portraying Stephen Hopkins (RI)), Virginia Vestoff (portraying Abigail Adams), David Ford (portraying Congressional President John Hancock (MA)), Ron Holgate (portraying , William Duell (portraying ,Ralston Hill (portraying Richard Henry Lee (VA)), Jonathan Moore (portraying Dr. Lyman Hall (GA)) and Charles Rule (portraying Joseph Hewes (NC)) all recreated their roles in the movie. The original Broadway production won 1969 Tony Awards for Best Musical, Best Featured Actor in a Musical (Ron Holgate) and Best Direction (Peter H. Hunt also directed the Broadway musical), and received nominations for Best Featured Actress in a Musical(Virginia Vestoff), and Best Scenic Design.
The final feature film of David Ford, Donald Madden (who also had one television appearance after this film), and Ray Middleton (who also had five television appearances and one animated voice role after this film).