"This fundamental right was protected by the Supreme Court in the early 20th century, from 1897 until the New Deal, during what is called the "Lochner era." Named after the historic liberty-of-contract decision by the Supreme Court, the Lochner era saw the Court strike down laws that interfered with the freedom of people to bargain over the terms of their own contracts. These included minimum-wage and maximum-hours laws, housing segregation laws, licensing laws and laws interfering with the freedom of parents to determine what kind of schooling their children receive. Then in 1937, as part of the "New Deal revolution," the Court abandoned its protection of these vital economic and personal liberties, contributing significantly to the tremendous growth in the nation's regulatory and welfare state over the past several decades."
Just for your general knowledge regarding freedom of contract and your right to dispose of your labor as you see fit.