Some of the textbooks, which are from three Christian publishers, also claim that evolution is untrue.
Education Secretary Betsy DeVos has rolled back protections for transgender students.
The child's mother pulled him out of the school following the incident.
The school chalked it up to an oversight issue.
"There is substantial evidence to support the allegation that the district subjected LGBTQ students to separate or different rules of behavior, sanctions or other treatment."
"I just want to cry because I have put my most precious possession in this teacher's hands this whole school year. To see this is how she thinks and feels for and about autistic children."
David Allen Turpin and with his wife, Louise Ann, are accused of abusing, imprisoning and starving 12 of their children for several years.
Rates of bullying have been found to drop when diverse stories are included in the school curriculum, according to the senator who sponsored the bill.
The student's mother said parents were not warned that the sixth graders would participate in an Underground Railroad simulation.
Nearly 40 school districts closed on Friday because too many teachers had requested leave to go to the rally in Kentucky's capital city, Frankfort.
The school district said a survey also found the public supported an initiative to arm select staff members with guns if it became legal in Pennsylvania.
Activist Mommy blogger Elizabeth Johnston is urging parents to take their children out of school to protest against sex education.
"This is a symbolic way for the students to participate in their actual education."
Stacy Bailey's supporters, including some students, have asked the school board to reinstate her.
Sixty-three percent of TEACH recipients from 2014 had their grants turn into loans "that they never intended to borrow."
The policy is aimed at ensuring that children from low-income families don't start their education at a disadvantage because they were enrolled in school later than others.
470 school districts in the U.S. have at least one school on a four-day week but a lack of available data means that number could be much higher.