Final answer:
The first MLB Collective Bargaining Agreement was negotiated in 1968, which generally led to improvements in players' rights and increased salaries.
Step-by-step explanation:
The first Collective Bargaining Agreement (CBA) in Major League Baseball (MLB) was negotiated in 1968. This historical negotiation impacted players' salaries significantly. Although not directly stated in your reference, the CBA played a role in improving players' rights and working conditions, which in turn, typically leads to increases in salaries over time. Prior to the establishment of CBAs, salaries were often low and controlled by the team owners, with players having limited leverage. The introduction of collective bargaining allowed players to negotiate as a unit, leading to many advancements, including higher salaries and better terms of employment.