We have employment agreements most of the time but its tonprotedt the company, not the worker. It allows them to change your duties or lay you off for no reason. That's called "right to work". It's different state to state. Red states always being "right to work" and fighting against worker protections and unions on the federal level every time. It's better in blue states, but not by much. Californiazl, for example, pays double overtime. But minimum wage is always lower than it should be because of red states on the federal level.