1. Linda the Librarian Teaches Sign Language. (1972)

Linda Bove in 1981. (Credit: Jeff Goode/Toronto Star via Getty Images)

Many people gained their first exposure to sign language—and deafness itself—from Linda, a human character Sesame Street introduced in 1972. Played by Linda Bove, who is hearing impaired in real life, Linda was Sesame’s resident librarian. In front of the cameras, Linda taught young children about the daily challenges for the hearing impaired, and behind the scenes, she worked hand-in-hand with writers to make sure the character was authentic and truly representative. After more than three decades on the show (the longest-running television role for a deaf character) Linda left in 2004.

2. Rosita Says “Hola” and “Hello.” (1991)

The Sesame Street character of Rosita at a 2003 event. (Credit: Chris Hondros/Getty Images)

The show has always tried to include a diverse cast, so it’s probably no surprise that when the United Sates experienced an influx of Mexican immigrants, producers tackled the issue head on. They introduced a bilingual Muppet, a little girl named Rosita La Monstrua de las Cuevas (the Monster of the Caves), who spoke both English and Spanish. Although Rosita was not the first bilingual Muppet on the show (that honor goes to Osvaldo, el Gruñón, a fellow Grouch that Oscar meets while walking around in the “real world”), she was the first Latina Muppet to join the cast full-time. In 2001, Rosita began teaching the Spanish word of the day, helping to educate children of all ages about Latin American culture and language.

3. Tarah Wheels On To The Street. (1993)

Sesame Street: The Wheels Go Round (Credit: Sesame Worksshop)

In 1993, the show introduced Tarah, a 9-year-old girl with osteogenesis imperfecta played by Tarah Schaeffer. Because of this genetic disorder, Tarah needed a wheelchair to get around, but didn’t let it slow her down. In her very first appearance she demonstrated for the other children (and some eager-to-learn-Muppets) how she did her wheelchair exercises, and even wowed them with a video tape of her winning a big race. In later episodes, she taught about accessibility ramps and performed in a wheelchair ballet. Schaeffer made regular appearances on the show over the next eight years, leaving for good in 2001.

4. Kami Brings HIV/AIDS Awareness to South Africa. (2003)

Kami, from South Africa’s “Takalani Sesame.” (Credit: KMazur/WireImage)

Despite advances in medicine and treatment for HIV and AIDS, South Africa remains one of the nations most affected by the virus. Wanting to combat ignorance and fear surrounding the disease, 5-year-old Kami was introduced as the first HIV-positive Muppet. Kami, whose name means “acceptance” in Tswana, first appeared on Takalani Sesame, the South African version of the show in 2003. Tami’s advice covers everything from how HIV is transmitted (or, more importantly, how it isn’t transmitted) to how to deal with grief when someone you love passes away from AIDS. Kami has become somewhat of an international spokesman for the cause, appearing alongside Desmond Tutu, Oprah Winfrey, Laura Bush, Whoopi Goldberg and Bill Clinton in order to raise awareness for the disease.

5. Mahboub Tries to Ease Middle East Tensions—Starting With Kids. (2006)

Israel: Rechov Sumsum Mahboub’s Friend (Credit: Sesame Street International Social Impact)

You don’t have to be an expert on the Middle East to know that tensions between Palestine and Israel have been an ongoing cause of political, cultural and social tensions in the area for a long time. In 2006, Rechov Sumsum, the Israeli version of the series, introduced Mahboub, an Arab-Israeli Muppet who spoke both Arabic and Hebrew. He would often be the conduit between groups of children and Muppets from all sides, showing that differences in language and culture shouldn’t keep people from being friends.

6. Segi Teaches Us About Self Acceptance.(2010)

Sesame Street: Song — I Love My Hair (Credit: Sesame Workshop)

In 2010, Joey Mazzarino, a puppeteer and head writer at Sesame Street, noticed that his daughter Segi, who is African American, was growing frustrated when playing with her Barbie dolls because they, unlike herself, had long, silky blonde hair. Unfortunately, Segi is definitely not alone in feeling this way, and even seven years later, diverse children’s toys are still not mainstream. Rather than just tell his daughter that her hair was beautiful, Mazzarino wrote a song called “I Love My Hair” and, with the help of the crew on the Street, created the now-series regular Muppet named Segi, to perform it. The song struck a chord with African American girls (and women) all over the world.

7. Zari Brings Girl Power to Afghanistan. (2016)

Afghan puppeteer Seema Sultani holds a muppet named “Zari” for a recording of the Afghan show “Baghch-e-Simsim”, or Sesame Garden. (Credit: WAKIL KOHSAR/AFP/Getty Images)

It’s not easy to make a children’s TV show in a war-torn country. Sesame Street has tried to do just that since 2011, when they introduced Baghch-e-Simsim, Afghanistan’s version of the beloved children’s program. In 2016, the company decided to tackle the issue of women’s rights the only way it knows how, with a colorful Muppet. Zari, whose name means “shimmering,” is the first Muppet of Afghan descent, and was created to provide young Afghan girls with a powerful and positive role model. In a country often under fire for its treatment of women, this is no small accomplishment.

8. Julia Battles Autism Stereotypes. (2017)

Sesame Street: Abby Cadabby & Julia Sing Sunny Days (Credit: Sesame Workshop)

Julia has been a part of the Sesame Street world since 2016, when she debuted as part of the show’s autism awareness initiative, “See Amazing in All Children.” And she was featured in books, mobile apps and online, helping children understand how to interact with people who have autism even before officially joining the show in 2017.

Because the autism spectrum is so wide-ranging, it’s impossible for Julia to represent every autistic child, so the show’s producers chose instead to focus on particular traits. For example, the decision to make Julia a girl was done to combat misconceptions that primarily boys are on the autism spectrum. Julia doesn’t talk much, and doesn’t make a lot of direct eye contact. She’s also sensitive to loud noises, a trait some children with autism exhibit, but she is also very smart and has a good memory. There’s no perfect way to depict autism with one character, but Sesame Street is hoping Julia, whose puppeteer has a son with autism, will encourage everyone to be more sensitive and empathetic to those with autism.