Back when TV shows like M*A*S*H, Cheers, Hill Street Blues, and other beloved hits of the 1970s and '80s first aired, fans didn't have the internet to connect them to the latest news and tidbits about actors, their lives, and behind-the-scenes insider information. Some gossip still made its way around, but there was no way of knowing all of the fun secrets, inside jokes, and hidden details behind favorite TV shows.

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It's fun to revisit some of the shows of yesteryear and discover just what was going on during filming, what the series was actually based on, and other fun hidden facts about the programs.

Updated March 6, 2020 by Richard Keller: As we near the 50th anniversary of this iconic show, more behind the scenes information comes out. Rather than ruin its 11-year run, these items provide insight into small part of the television universe that was the 4077th. We've updated this list with a few more items that should make you nod in understanding about some of the show's quirks.

More Christmases

Hawkeye talking to a man dressed as Santa

The U.S. entered the Korean conflict at the end of June 1950. They remained until the armistice was signed in July of 1953. That means doctors and nurses at the numerous Mobile Army Surgical Hospitals were there for three Christmases.

Unfortunately, the producers of M*A*S*H may not have realized this. During its 11-season run, the staff at the 4077th celebrated the holiday four times. Technically, one was a Boxing Day episode, but the start of the program took place on the night of Christmas.

Radar's Hidden Fingers

Radar and Hawkeye

If you look closely at Gary Burghoff's appearances on the show, you'll notice his left hand tends to be hidden. It will either be inside a glove, behind a clipboard, or in his pocket. The reason for this was three of his fingers were deformed to a birth defect.

Though not always the case, it was something fans of the series learned later. We wouldn't have realized it at the time. Especially in the episodes where he played the drums. A skill he developed despite the deformity.

B.J.'s Mustache

When Mike Farrell's Captain B.J. Hunnicutt replaced Trapper John in the show's fourth season, he was a young, clean-shaven, mild-mannered doctor drafted into the Korean War. Though he did show some stubble from time to time, he remained without a full face of hair during his first few seasons.

However, before the show's seventh seasons premiered, Farrell's best friend on the show and in real life, Alan Alda, asked him to grow a mustache. The main reason was to distinguish the two characters, who seemed quite similar. Interestingly, the growth of the mustache also coincided with a change in B.J.'s attitude toward the war and the military in general.

Real and Fake Wildfires

In the series finale of M*A*S*H, the staff has to bug out due to an incoming brush fire. When they return to the site, all that remains are the foundations of the wood and metal buildings. They were destroyed by the enormous heat of the wildfire.

This was not something added to the original script. In reality, the show's set on the Fox Ranch in the Santa Monica Mountains was devastated during filming of the final episode. It was then that Alan Alda and the rest of the writers incorporated it into the story.

Signpost Hometowns

Out of the characters on M*A*S*H*, the most famous is not Hawkeye Pierce or Maxwell Klinger. It's the signpost that sat in the middle of the camp. Part of the original cast, the amount of signs grew as the show continued. In a season six episode, Major Charles Winchester added one for his hometown of Boston.

However, the home bases of some of the characters were never added. For instance, Hawkeye didn't have one for Crab Apple Cove. Similarly, Radar never put one up for Ottumwa, Iowa. On the other hand, B.J. didn't have to add one for Mill Valley as San Francisco was already on the signpost.

There's A Book

After MASH starring William Christopher, Jamie Farr, and Harry Morgan

Did you know that M*A*S*H was based on a novel? Richard Hooker's book MASH: A Novel About Three Army Doctors is the story of the 8055th Mobile Army Surgical Hospital in Korea, and while it's not nonfiction, it is based on the experiences and knowledge of former surgeon in the military Dr. H. Richard Hornberger, who wrote the book with writer W. C. Heinz after serving in the Korean War. Hooker was merely their shared pen name.

Hornberger, who was described as a good surgeon with a sense of humor, worked in a VA hospital following the war before opening his own practice. He wrote his novel in 1956.

The Writers Had Secrets

Henry Blake farewell in MASH

Most of the cast had no idea when Henry Blake was being offed from the show. Only Alan Alda knew this secret. The entire cast received scripts and had to act out the majority of the episode before they each received a copy of the final page before their end of the season party, which had to be a shocker for the entire cast.

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Speaking of writing, M*A*S*H also had an incredible pilot episode turnaround. The entire script was completed in just three days by writer Larry Gelbart. Another weird detail: when cast members complained about the script too much, writers changed the script to make actors wear parkas, pretending it was cold weather, when it was 90 to 100 degrees on set.

Laugh Tracks Were Quiet On Purpose

Fans who paid attention to the show noticed that even when jokes were cracked in the operating room, there was no laugh track while Hawkeye and company were at work. The track was muted for these scenes, and given the serious nature of the show, producers pushed for no laugh track at all.

As a compromise, CBS not only muted the laughs during the operating scenes, but also lowered the volume of the laughter throughout the series, making it less raucous than the normal canned laughs of a comedic series. It was a decent agreement to help relieve the tension of the show during its more dramatic moments.

Lots Of Future Stars Made Appearances

Like many great long-lasting TV shows, many of the guest stars who appeared in M*A*S*H went on to become A-list actors. Director and actor Ron Howard had a notable appearance as a Marine on the show. Shelley Long, Leslie Neilson, Laurence Fishburne, Blythe Danner, John Ritter, Ed Begley, Jr., and Rita Wilson all had parts on the show at one point, as did Teri Garr, Andrew Dice Clay, and George Wendt.

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One of the most beloved actors of the '80s, Patrick Swayze, was even on the show. He played a soldier who not only suffered an injury but also had leukemia.

The Time Capsule's Fate Wasn't Very Exciting

Fans who tuned in for the series penultimate episode, "As Time Goes By," know that there was a time capsule buried by the characters. Anyone who loved the show would have thought that it made a poignant moment and would be just as exciting once the time capsule was found, but the person who discovered it wasn't very impressed, according to actor Alan Alda.

Once the land was sold, the time capsule was discovered only months after the series ended, which likely affected its relevance to the construction worker who found it and asked what to do with it. At least it wasn't destroyed, as many time capsules unfortunately are.

Alan Alda Made History With The Show

Between directing 31 episodes and writing 13 episodes while continuing to act on the show, Alan Alda made history as the first person to win an Emmy for writing, directing, and acting in a show.

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From his memoirs to his involvement in kids' science events, hosting Scientific American Frontiers to winning multiple Emmys, Golden Globe Awards, and other forms of recognition, Alda has remained a popular actor throughout his lifetime. He has most recently appeared on Ray Donovan, The Longest Ride, The Blacklist, and Horace and Pete. He's also been on 30 Rock, The West Wing, ER, The Big C and made guest appearances on many other shows.

Patriotism Was Enforced

Although the show depicted many truths to the war, it also avoided some that painted the troops in an unpatriotic light. CBS refused to give the green light to an episode where soldiers would stand outside in the cold to purposefully become ill enough to be sent home, even though writers stressed that this was a true detail regarding soldiers that should at least be shown to audiences.

There were plenty of other details that were either omitted, changed or exaggerated as well, including the length of the war. The Korean War lasted under four years, yet the show itself ran for 11 years.

It Had The Most-Watched Episode In The History Of American TV

Mash series finale

You think a lot of people will be tuning in to see the series finale of Supernatural this year, or Law and Order: SVU (whenever that happens)? It probably won't compare to the sheer numbers that watched the finale of M*A*S*H on Monday, February 28, 1983.

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The episode, “Goodbye, Farewell and Amen," was two and a half hours long and viewed by a whopping 77% of the people watching TV that night, or 121.6 million people. No matter who pitches a TV show today, most writers and producers couldn't dream of hitting those numbers.

Some Actors Were Soldiers

Wayne Rogers in MASH

Some of the actors who starred in M*A*S*H had actual military experience to draw from when it came to their scenes. Jamie Farr and Alan Alda, who played Klinger and Hawkeye, respectively, were both military men. Both served in the Army. Farr was stationed in Japan and Korea, and Alda spent six months in Korea with the Army Reserve.

Other actors from the TV show served in additional branches of the military. Wayne Rogers, who portrayed Trapper John McIntyre, was in the U.S. Navy, and Mike Farrell, who played B.J. Hunnicut, served in the Marine Corps.

Klinger Was Cast For A Single Episode

Klinger was only meant to appear in one episode of the show, and the character wasn't even in the book. But audiences took to the bit character that he was written in as a regular on the show.

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Imagine what M*A*S*H would have been like without Jamie Farr's character! It's unfortunate that the role was swapped for a heterosexual man who only cross-dressed to attempt to get out of the war, as the character was supposed to have been gay, which would have been some much-needed representation on television in the 1970s and '80s. Audiences still looked forward to seeing which outfit Klinger would wear next and what stunts he'd pull to attempt getting discharged.