It’s commonly believed that school kids started taking summers off in the 19th century so they’d have time to work on the farm. Summer vacation has little to do with tilling fields and more to do with city kids playing hooky.
Farm kids never had summers off. They stayed home during the spring and fall, when crops needed to be planted and harvested. City kids hit the books all year long.
But as cities got denser, they got hotter. That’s when America’s swelling middle and upper class families started hightailing it to the cooler countryside. School attendance wasn’t mandatory then, and classrooms were half-empty each summer.
Working adults were getting more time to themselves than ever before. Advocates for vacation time also argued (incorrectly) that the brain was a muscle, and like any muscle, it could suffer injuries if overused. They argued that students shouldn’t go to school year-round because it could strain their brains. Air conditioning was decades away...
By the turn of the 20th century, urban districts had cut about 60 schooldays from the most sweltering part of the year. Rural schools soon adopted the same pattern. Business folks obviously saw an opportunity here. The summer vacation biz soon ballooned into what is now one of the country’s largest billion-dollar industries.