A picture book for second graders about a family with two moms. A lesson for fourth graders about Gold Rush era stagecoach driver Charley Parkhurst, who was born a woman but lived as a man.

These are just some of the ways U.S. public school students will learn about LGBTQ - lesbian, gay, bisexual, transgender queer - history in a growing number of states moving to mandate inclusive K-12 curriculum. It is the latest chapter in a decades-long push to teach students about the trials and contributions of marginalized communities - from suffragettes to black Americans - whose stories have often been absent from classrooms.

At the forefront is California where the curriculum became law in 2011. New Jersey became the second state in January, limiting its mandate to middle- and high-school students.

On Thursday, Colorado lawmakers voted to mandate LGBTQ curriculum for K-12 public school students. Governor Jared Polis, the nation's first openly gay governor, will review the final bill before deciding whether to sign it into law, a spokeswoman said.