I assume the “RLA” in your question stands for the “Railway Labor Act”, and have edited your question accordingly.
The act is a U.S. Federal Law governing labor relations in the railway and airline industries. It was passed in 1926, then amended twice, in 1934 and 1936.
Focus: the act is intended to preclude strikes in vital transportation industries by substituting bargaining, mediation and arbitration for strikes.
History: As a result of the Great Railroad Strike of 1877 the U.S. Congress passed the arbitration act of 1888. The act was a failure, and did nothing to solve problems caused by unions. The government then passed the Adamson Act in 1916. It established the 8-hour workday at same pay as previous 10-hour day. A companion act in the same year gave the President authority to take control of transportation systems to transport troops. In 1917 the Railroad Labor Board RLB was established. It provided non-binding resolutions to labor disputes. The unions shunned the RLB. As a result, the RLA was achieved through negotiations between the railways and the unions. It provided negotiation and mediation procedures, and methods for resolving minor disputes. Strikes were only permitted after exhausting negotiations and mediation procedures.
See the reference for details, and related acts such as the National Labor Relations Act (NLRA), and the creation of the National Labor Relations Board (NLRB).
Back in the 1870's, railroad strikes were so violent and ghastly, that federal troops usually had to be called in to restore order. At the time, employees worked under dangerous conditions, had no sick leave or injury compensation, and were often overworked and underpaid. So, in 1898, Congress passed the Erdman Act which helped conditions for the employees, but was far from being a permanent solution to the problems. It was more like putting a bandaid on the wound, rather than getting the bleeding stopped! So, in 1913, Congress passed an even better Act--The Newlands Act. It was more effective and served the Railroad industry up until the federal govenment nationalized it in 1917. Then, in 1920, Congress established the Railroad Labor Board which gave control of the railroads backs to the owners. It soon proved it was a total flop and eventually many railroads refused to have anything to do with it! Something had to be done! Enter the RLA.
"The RLA was the product of negotiations between the major railroad companies and the unions that represented their employees." It was born out of necessity and trial and error as to what worked over the years and what didn't. The RLA uses arbitration boards to settle disputes and it works! In fact, it worked so successfully, in 1936 it was amended to include the airline industries. Later on, in 1951, Congress legalized the union shop, which is nothing more than a agreement made by an employer who belongs to a union that he can hire anyone to work for his company, union or non-union, but the non-union worker has to eventually join the union to stay employed.
Many benefits and privledges have come to railroad and airline employees as a result of this Act, too many to enumerate in this post. I suggest reading the full text of the articles found at http://en.wikipedia.org/wiki/Railway_Labor_Act and http://en.wikipedia.org/wiki/Union_shop
You ask an interesting question. I googled RLA and found over 30 possible definitions. Perhaps you can spell out RLA so that I can provide you with an answer. Thanks!