Sherry Read said she was amazed to learn that 100-year-old chalkboard lessons had been found in her classroom, among others, during a renovation of Emerson High School in Oklahoma.
"It's like walking through an art museum," she told ABC News. "You just sit there and stare at every picture."
Read, who teaches math of finance and geometry to juniors and seniors, said the school was built back in 1911, just six years prior to the teachings on the blackboards.
The drawings were uncovered behind all four of the classroom's existing chalkboards on June 2, when construction workers were remodeling the second floor of the school.
"It's kind of been a mystery trying to figure out why this was left up there," Read said. "They put music up there, math problems up there. It's seeing a glimpse of the past and what they had to work with and the penmanship is just awesome."
The untouched boards revealed lessons in math, music, a written history on the pilgrims, and a countdown until Christmas day.
The writings were dated on December 1917.
"It's been neat just to touch history," Read said. "To see this being preserved just makes my heart filled with joy. Knowing that this was behind my wall all this time is pretty fascinating."
Still school is out for the summer, students of Emerson have yet to see the chalkboards in person.
Read said the administration at Emerson is exploring plans on how they can preserve the writings.