It seems to have changed in past decades. When I was in school in 70s/80s, everyone brought their lunch. And we weren't in a well-off area or anything.
As a sibling comment noted, the National School Lunch Program started in 1946. [1]
The School Breakfast Program started in the 1960s/70s. [2]
More recently, in 2010, the Healthy, Hunger-Free Kids Act was passed which enabled the Community Eligibility Provision which lets low income area schools offer free food to all kids without individual application/qualification. [3][4]
Various schools I went to in the 90s/00s had some kids bringing their lunch, some kids paying the school for lunch, and some getting free lunch (because they were poor enough to qualify).
The School Breakfast Program started in the 1960s/70s. [2]
More recently, in 2010, the Healthy, Hunger-Free Kids Act was passed which enabled the Community Eligibility Provision which lets low income area schools offer free food to all kids without individual application/qualification. [3][4]
Various schools I went to in the 90s/00s had some kids bringing their lunch, some kids paying the school for lunch, and some getting free lunch (because they were poor enough to qualify).
[1] https://www.fns.usda.gov/nslp
[2] https://www.fns.usda.gov/sbp/factsheet
[3] https://www.usda.gov/about-usda/news/press-releases/2014/05/...
[4] https://www.fns.usda.gov/cn/cep