My reaction as well. I was homeschooled but most of my friends were not. Never heard of any classes in humanities. They didn't get much history either. :(
It’s probably the new politically correct term for “Social Studies” which replaced GEOGRAPHY back in the 70s.
I went through Oregon junior high and high school in the ‘70s. English classes in high school were stratified into Honors English, English, and Humanities. I forget how many English credits were required to graduate. Humanities was a way to assure that pretty much anyone could fulfill the requirement.