THEN AND NOW: The cast of 'American Horror Story' season one

Britton played Vivien, the matriarch of the small Harmon family. Vivien moves to Los Angeles with her husband and daughter in an attempt to put their past troubles behind them. After dealing with her husband's marital affair, she becomes pregnant with twins.

Britton was nominated for an Emmy Award for playing Vivien.

She had been working in TV for 15 years but, at the time, was known for her role in "Friday Night Lights," which also earned her an Emmy nomination.

After the first season of "American Horror Story," Britton landed the role of Rayna Jaymes in the hit series "Nashville." She earned another Emmy nomination for the role.

After that, she took a part in "9-1-1," another series by "American Horror Story" creator Ryan Murphy. In 2018, she starred in "Dirty John" and returned to the "American Horror Story" franchise to reprise her role as Vivien in season eight, "Apocalypse."

Most recently, she starred in HBO's acclaimed series "The White Lotus" in 2021.

At the beginning of the season, Dr. Ben Harmon, a psychiatrist, moves his small family to Los Angeles after cheating on his wife, Vivien. His world starts to unravel when he finds out his wife and his mistress are pregnant at the same time.

In 2011, McDermott was known for his role in "The Practice" — for which he earned an Emmy nomination and won a Golden Globe — before taking the part of Ben.

In 2013, he played Duncan Carlisle in "Hostages" and then Jack Larsen in "Stalker" in 2014. He has returned to the "American Horror Story" universe several times, reprising his role as Dr. Ben Harmon but also playing other characters like Johnny Morgan and Bruce.

He continued working with Ryan Murphy, getting a role in "The Politician" in 2019 and another in "Hollywood" in 2020. He earned an Emmy nomination for the latter.

Most recently, he has been in "Law and Order: Organized Crime."

In the first season of "American Horror Story," Tate is a teenage sociopath whom Dr. Harmon is treating. He quickly infiltrates the family and starts dating the daughter, Violet.

Before taking on the role of murderous Tate, Peters was seen in the Disney Channel's "Phil of the Future" and "One Tree Hill."

Peters has worked closely with Ryan Murphy through the years. For starters, the actor has appeared in eight seasons of "American Horror Story," playing various roles like the ghost of a serial killer, a cult leader, and even a hairdresser. Peters also played Stan Bowes in Murphy's series "Pose."

Outside of Murphy's universe, Peters played Peter Maximoff in the "X-Men" series and appeared in the hit series "WandaVision." Most recently, he starred alongside Kate Winslet in HBO's "Mare of Easttown" and earned himself his first Emmy nomination.

He's expected to return to the "American Horror Story" franchise in season 10, titled "Double Feature."

Farmiga plays Violet, the angsty teenage daughter in "Murder House" who becomes entangled with the dangerous Tate.

It was her first major TV role.

Farmiga starred in movies like "The Bling Ring" in 2013, "6 Years" in 2015, and "The Nun" in 2018.

The actress returned to "American Horror Story" a few times, playing Zoe Benson in "Coven" and Sophie Green in "Roanoke."

Constance is the Harmons' nosy next-door neighbor who once lived in the house. During the season, she vows to take one of Vivien's twins because she has lost all four of her children. Lange brought the character to life so well that she earned an Emmy for the role.

Lange was no stranger to awards, however. Before the series, she already had another Emmy Award — for best actress for "Grey Gardens" in 2009 — and two nominations under her belt. She also had two Academy Awards and six nominations dating back to 1983 — she won best supporting actress for "Tootsie" in 1983 and best actress for "Blue Sky" in 1995.

After "Murder House," she returned for season two to play an evil nun in "Asylum" and a witch in "Coven" in season three. She earned an Emmy nomination for the first and won an Emmy for the latter. She was nominated again for roles in other seasons titled "Freak Show" and "Apocalypse."

Lange also starred in Murphy's other series "Feud," playing Joan Crawford, and earned two Emmy nominations as actress and producer.

Most recently, she appeared in Murphy's "The Politician" in 2019.

Larry Harvey is another previous owner of the Harmon house and claims he earned his scars by setting his wife and children on fire. He's also in love with Constance Langdon and would do anything for her.

O'Hare earned an Emmy nomination for playing Larry in 2012.

Prior to the show, the actor played bit roles in several TV shows and movies. But he was most well-known for his parts in "Brothers and Sisters" and "True Blood."

Since season one, O'Hare has played a butler in "Coven," a transgender employee in "Hotel," and a troubled actor in "Roanoke." The actor earned another Emmy nomination when he played a con artist in the third season.

He's also currently appearing in HBO's new witch-focused series, "The Nevers." He will also appear in the upcoming 10th season of "American Horror Story."

At the beginning of the season, Mara is introduced as Hayden, the unstable former student Ben had an affair with before moving to Los Angeles. She quickly reveals she is pregnant with his baby and intends on keeping it.

At that time, Mara was known for various roles in TV shows and movies, including "24" and "Entourage."

In 2013, Mara took on a career-defining role as political reporter Zoe Barnes in Netflix's "House of Cards." She was nominated for an Emmy for that role.

After that, she switched to movies and then returned to TV in 2018 for Ryan Murphy's series "Pose." Most recently, she starred in Hulu's "A Teacher," playing a teacher who has an affair with her student.

Once Constance's maid and now a ghost of the house, Moira continues taking care of the Harmon family. However, she is shown as an elderly woman when women see her and a beautiful, younger woman in the eyes of men.

The actress earned an Emmy nomination for the role.

At the time, Conroy was best known for her part as Ruth Fisher in "Six Feet Under," for which she earned four Emmy nominations and won a Golden Globe.

Since season one, Conroy has taken on several other roles in TV shows, including "Castle Rock," "Casual," and "How I Met Your Mother."

But the actress always made sure to return to "American Horror Story," playing the angel of death in "Asylum," a wealthy woman in "Freak Show," and a cult member in "Apocalypse." Most notably, she played Myrtle Snow in "Coven," which earned her yet another Emmy nomination.

Conroy is set to appear in the 10th season of "American Horror Story."

Whenever men would lay eyes on the maid, she appeared as a young woman, played by Breckenridge.

The actress was known for her roles in teen comedies like "She's The Man" and "Big Fat Liar" at the time.

After 2011, Breckenridge went on to act in "The Walking Dead," "Family Guy," and "This Is Us."

In 2019, she took on the lead role in Netflix's "Virgin River," which just premiered its third season.

Nora Montgomery is the ghost of a wealthy woman from the '20s whose husband built the house the Harmons just moved into.

Rabe was a relative unknown when she took the part.

Rabe has become a star in the "American Horror Story" universe, playing a shy nun in "Asylum," a witch in "Coven," and another ghost in "1984."

The actress was most recently seen in HBO's "The Undoing" opposite Nicole Kidman. She also starred in Amazon's "Tell Me Your Secrets."

She will return to the "American Horror Story" universe in "Double Feature."

Addie is often seen outside the house, warning the Harmons about the evil that surrounds the building. The role was Brewer's big break.

She played a witch in "Coven," a ventriloquist in "Freak Show," and a cult member in "Apocalypse."

She's appeared in other projects too, such as ABC's "Station 19" and the Tom Holland-led movie "Cherry."

Dr. Charles Montgomery built the home for his wife in the '20s off the fortune he made being a celebrity surgeon who also administered abortions.

When Ross took the role, he was known for playing Alby Grant in HBO's "Big Love" from 2006 to 2011.

Ross returned to "American Horror Story" when he reprised Dr. Charles Montgomery in "Hotel."

The actor also appeared in other TV shows like "Magic City," "Revolution," and "Silicon Valley."

Billie Jean Howard is a medium who only appears in a few episodes of season one and works closely with Constance and Violet.

Before "Murder House," Paulson appeared in many TV shows and movies, including "Jack & Jill," "What Women Want," "Deadwood," and "Studio 60 on the Sunset Strip."

Paulson returned for season two, playing a journalist who gets trapped in a mental-health facility in "Asylum." She earned an Emmy nomination for the role.

From there, Paulson took on the largest roles in the following seasons, playing a witch in "Coven," a woman with two heads in "Freak Show," and an addict in "Hotel." She earned four more Emmy nominations for her work on the series.

Beyond "American Horror Story," Paulson worked closely with Ryan Murphy on another series, "American Crime Story," playing Marcia Clark in "The People v. O.J. Simpson." She won an Emmy for that role.

Paulson also appeared in a few blockbuster movies including "Ocean's 8," "Bird Box," and "Glass." Additionally, she starred in Netflix's "Ratched" and Hulu's "Mrs. America."

This year, she will return to "American Crime Story" — this time about President Bill Clinton's impeachment — to play Linda Tripp.