<P> In 1962 US President John F. Kennedy issued Executive Order #10988 which permitted federal employees to form trade unions but prohibited strikes (codified in 1966 at 5 U.S.C. 7311 - Loyalty and Striking). In 1981, after public sector union PATCO (Professional Air Traffic Controllers Organization) went on strike illegally, President Ronald Reagan fired all of the controllers . His action resulted in the dissolution of the union . PATCO reformed to become the National Air Traffic Controllers Association . </P> <P> In the U.S., as established in the National Labor Relations Act there is a legally protected right for private sector employees to strike to gain better wages, benefits, or working conditions and they cannot be fired . Striking for economic reasons (i.e., protesting workplace conditions or supporting a union's bargaining demands) allows an employer to hire permanent replacements . The replacement worker can continue in the job and then the striking worker must wait for a vacancy . But if the strike is due to unfair labor practices (ULP), the strikers replaced can demand immediate reinstatement when the strike ends . If a collective bargaining agreement is in effect, and it contains a "no - strike clause", a strike during the life of the contract could result in the firing of all striking employees which could result in dissolution of that union . </P> <P> Another counter to a strike is a lockout, the form of work stoppage in which an employer refuses to allow employees to work . Two of the three employers involved in the Caravan park grocery workers strike of 2003 - 2004 locked out their employees in response to a strike against the third member of the employer bargaining group . Lockouts are, with certain exceptions, lawful under United States labor law . </P> <P> Historically, some employers have attempted to break union strikes by force . One of the most famous examples of this occurred during the Homestead Strike of 1892 . Industrialist Henry Clay Frick sent private security agents from the Pinkerton National Detective Agency to break the Amalgamated Association of Iron and Steel Workers strike at a Homestead, Pennsylvania steel mill . Two strikers were killed, twelve wounded, along with two Pinkertons killed and eleven wounded . In the aftermath, Frick was shot in the neck and then stabbed by Alexander Berkman, surviving the attack, while Berkman was sentenced to 22 years in prison . </P>

​when a firm refuses to allow union employees to enter the workplace the action is known as a