This analysis tracks the history of guest worker programs and their rules as a policy to manage migration flows from Mexico. The most important lesson from this history is that the government can impose rules that make a guest worker program functionally unusable for employers and workers, resulting in illegal immigration. Caps on visas and limits on the types of jobs that the workers can perform inevitably cause illegal immigration to reappear. Wage regulations that artificially increase the cost of hiring far beyond market wages cause employers to seek to hire workers outside of the system. Any highly regulated guest worker program must resort to heavy‐handed enforcement measures to keep illegal immigration from spiraling out of control again.