United States labor law sets the rights and duties for employees, labor unions, and employers in the United States. Labor law's basic aim is to remedy the "inequality of bargaining power" between employees and employers, especially employers "organized in the corporate or other forms of ownership association". Over the 20th century, federal law created minimum social and economic rights, and encouraged state laws to go beyond the minimum to favor employees. The Fair Labor Standards Act of 1938 requires a federal minimum wage, currently $7.25 but higher in 29 states and D.C., and discourages working weeks over 40 hours through time-and-a-half overtime pay. There is no federal law, and few state laws, requiring paid holidays or paid family leave. The Family and Medical Leave Act of 1993 creates a limited right to 12 weeks of unpaid leave in larger employers. There is no automatic right to an occupational pension beyond federally guaranteed Social Security, but the Employee Retirement Income Security Act of 1974 requires standards of prudent management and good governance if employers agree to provide pensions, health plans or other benefits. The Occupational Safety and Health Act of 1970 requires employees have a safe system of work. A contract of employment can always create better terms than statutory minimum rights. But to increase their bargaining power to get better terms, employees organize labor unions for collective bargaining. The Clayton Act of 1914 guarantees all people the right to organize, and the National Labor Relations Act of 1935 creates rights for most employees to organize without detriment through unfair labor practices. Under the Labor Management Reporting and Disclosure Act of 1959, labor union governance follows democratic principles. If a majority of employees in a workplace support a union, employing entities have a duty to bargain in good faith. Unions can take collective action to defend their interests, including withdrawing their labor on strike. There are not yet general rights to directly participate in enterprise governance, but many employees and unions have experimented with securing influence through pension funds, and representation on corporate boards. Since the Civil Rights Act of 1964, all employing entities and labor unions have a duty to treat employees equally, without discrimination based on "race, color, religion, sex, or national origin". There are separate rules for sex discrimination in pay under the Equal Pay Act of 1963. Additional groups with "protected status" were added by the Age