Yellow dog contracts date back to the 1870s. They appeared in the form of written agreements, commonly referred to as "iron" or "infamous" documents with anti-union agreements. When an employee signed one of these agreements, he or she waived his or her right to join the union responsible for his or her profession. By 1887, however, 16 states had determined that it was considered criminal activity to force employees to sign these agreements. However, yellow dog contracts do not always take the form of non-union agreements. Sometimes they appear as non-compete obligations that explicitly prohibit an employee from working with a company`s direct competitor, which can harm their current employer in the process. Yellow dog contracts are particularly advantageous for employers because they allow a company to take legal action against employees who engage in activities prohibited by the agreement. 29 U.S.C § 103(a)-(b): Inapplicability of Yellow Dog Contracts An agreement between an employer and an employee in which the employee agrees not to join or remain a member of a professional or employer organization. Yellow dog contracts are usually illegal.
Although banned in the private sector by the Norris-LaGuardia Act in 1932, yellow dog contracts in the public sector, including many government jobs, such as teaching, were allowed until the 1960s, beginning with a precedent established in 1915 with Frederick v. Ownens.  In 1910, the International United Brotherhood of Leather Workers on Horse Goods organized a major strike. However, this strike failed, leading many companies in the industry to demand verbal and written agreements from workers that they would leave their unions and not join the unions in the future if they wanted to return to work. The term "yellow dog" was originally coined in 1921 and published in a number of important publications aimed at workers who were still members of a union. The yellow dog contract was a tool used by employers before the New Deal era to prevent workers from bargaining collectively. Through a yellow dog contract, a worker agreed not to join or remain a member of a workers` organization and to leave his job if he joined one. At a time in our history, when the courts shaped the law in such a way that its main beneficiary was industrial capitalism, contracts with the yellow dogs were enforceable, even though workers had little choice in accepting their terms. Workers have signed such contracts or lost the opportunity to work. In fact, a yellow dog contract blackmailed an employee into promising not to join a union; His so-called free choice to take a job or look for work elsewhere turned out to be a choice between blackmail or blacklisting. On the one hand, yellow dog contracts deprived workers of their contractual freedom. However, the courts have taken a different view.
With the Norris-La Guardia anti-injunction law of 1932, Congress declared that "yellow dog" contracts were contrary to public order and that the courts could not enforce them. After the passage of the Wagner Act in 1935, the National Labour Relations Board ruled that employers were pursuing unfair labor practices to require workers to sign such an agreement. As a result of these two actions, the "Yellow Dog" contract disappeared from the work scene. By adding this "non-adherence" clause to its contracts, Coppage violated state law that prohibited all forms of anti-union contracts. This case is an example of yellow dog treaties violating the Fourteenth Amendment – in particular, the amendment`s due process clause. There are generally two main types of yellow dog contracts: The term "yellow dog" was originally coined in the 1920s and means how employees were perceived in the eyes of their peers for the signing rights they were entitled to in the U.S. Constitution. For example, it was common at the time for people to say things like, "What kind of person is willing to be a `yellow dog` and sign their rights just to get a job?" Until 1932, the Norris-LaGuardia Act prohibited yellow dog contracts from existing in the private sector. However, until the 1960s, they were still allowed in the public sector, even in federal jobs. At this point, the history of the yellow dog contract ended, as all yellow dog contracts from that moment on were considered illegal and unenforceable. A yellow dog contract was beneficial for the employer because it gave the employer recourse if its employees committed a mutiny against the company.
In 1932, a new philosophy was brought into play that the government should remain outside the right of workers to organize. .