In the U.S. they are state laws varying state-to-state. Find out if your state has a legal homeschool association. You have to know the laws. For example visit https://hslda.org.

P.S. Clarification: Idaho DOES have homeschooling laws but because there is so much freedom it seems like there isn’t one. But there is a law that says it’s legal, and that it’s about educating children well etc. I’m very grateful for the Idaho education freedom. Thank you, Idaho.