The term yellow dog appeared in the spring of 1921 in prominent articles and editorials devoted to the subject, which appeared in the working press. Typical was the comment of the editor of the United Mine Workers` Journal: In the 1870s, a written agreement promising not to join a union was commonly referred to as the “Infamous Document.” This reinforces the belief that Us employers have deliberately followed English precedents in their use of individual contracts. This anti-union promise was also called the “iron document”, and from that time until the end of the 19th century, “battleship” was the common name for the non-union promise. Beginning in New York in 1887, sixteen states wrote statements in their statutes that made the strength of employees not to agree not to join unions a criminal act. The United States Congress included in the Erdman Act of 1898 a provision on airlines engaged in interstate commerce. A yellow dog contract (a yellow dog clause of a contract or an iron oath) is an agreement between an employer and an employee in which the employee agrees not to be a member of a union as a condition of employment. In the United States, these contracts were widely used by employers until the 1930s to prevent the formation of unions, most often by allowing employers to take legal action against union organizers. In 1932, Yellow Dog treaties were banned in the United States under the Norris-LaGuardia Act.   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 that the agreement prohibits. In 1932, however, a new school of thought emerged that proposed the idea that the government should not be involved in banning workers` organizational rights. This led to the passage of the Norris-LaGuardia Act, which ended yellow dog contracts in court. The term “yellow dog” was originally coined in the 1920s and means what employees were seen in the eyes of their colleagues to sign rights to which they were entitled under 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?” A yellow dog contract was advantageous for the employer because it provides the employer with legal recourse in the event that its employees initiate a mutiny against the company. In 1932, a new philosophy circulated that the government should stay out of workers` right to organize. This led to the passage of the Norris-LaGuardia Act and the end of contracts with yellow dogs, which were legally maintained. Nowadays, yellow dog contracts most often appear in the form of non-competition clauses. These are usually introduced by employers if they have a legitimate interest in preventing employees from working for a directly competitive company and potentially affecting the future success of their business. .