The Federal one states you cannot be employed on a part or full time basis until the age of 14. At that age you can work under 20 or so hours on the weekend. This stays until the age of 16, at which you can work part or full time, meaning up to the 40 hour federal workweek. 18 years of age gains you employment to most places and there are no restrictions on how much you can work.
For more Child Labor Law Limit, visit www.StateandFederalPoster.com
they sell Labor Law Posters with regulations of child labor law in various states. Most states have mandatory notices they must post regarding child labor.