It is quite rare to find LGBTQ+ history in children’s school textbooks.

Despite the lack of representation, LGBTQ+ history is American history, but not many schools teach it to their students, leaving an increasing amount of LGBTQ+ students disconnected because they do not see a core piece of their identity in classrooms.

To change that, one nonprofit, History UnErased, is making sure LGBTQ+ topics are being taught in schools to provide the untold stories of significant events in LGBTQ+ history.

History UnErased was co-founded in 2015 by former classroom educators to provide K-12 schools with the training and resources needed to properly teach LGBTQ+ history.

The organization provides teacher training to help teachers discuss LGBTQ+ topics to their students. History UnErased also provides a syllabus for teachers who need help organizing their lesson plans.

Other topics range from pop culture, politics, and media.

Debra Fowler, co-founder and executive director of History UnErased told CBS News that its curriculum, “Provisions and Connections,” provides topics from Jamestown in 1629 through to the 21st century.

“Most people dont realize that LGBTQ history is missing from k-12 classrooms, and that absence has been doing harm,” she said.

Fowler said the curriculum reflects over seven years of research and development. In the process, she sought the help of many historians and classroom educators to condense many years of LGBTQ+ history into a syllabus.

“Young people today are surrounded by LGBTQ topics everywhere,” she said. “Now History UnErased is bringing the curriculum into the classrooms so students can fully understand the path and progression of these topics.”

There are over 1,200 schools all across the nation using the curriculum from History UnErased, including all of New York City’s K-12 schools, and many in Washington state and New Jersey.

Suzanne Riveiro, a teacher at Bronx High School for the Visual Arts, spoke with CBS News about the importance of adding an inclusive lesson plan, such as the one created by History UnErased.

“This curriculum came to me and it had to do with identity and how people really spoke up for what they believe in,” she said. “It was perfect for my class.”

A majority of her students are sophomores through seniors, which is a crucial point in life where many people begin to open up about their identity and start expressing themselves.

Fowler, who experienced many instances of discrimination when she was in the military in 1986, does not want any student to go through what she has, and is a main reason why she started History UnErased.

“At that time, one of the entrance forms had a question that asked am I a homosexual,” she said. “I checked no, I knew that was a lie.”

Fowler knew she was gay, and so did the military.

“I was dishonorably discharged from the military,” said Fowler.

After the miserable experience, she became an educator in South Korea and fell in love with teaching.

“When I returned to the United States, I taught at a diverse high school for many years working with refugee children,” she said.

Years later, she founded History UnErased and said she is proud to see the success her program has found.

“We know that this content affirms lives, and saves lives,” said Fowler.

For more information about History UnErased, visit its website.