Which two groups carried out collective bargaining in the 19 century?

In the 19th century, collective bargaining was primarily carried out between labor unions and employers. Labor unions, representing workers' interests, sought to negotiate better wages, working conditions, and benefits. On the other side, employers, often organized into associations or representing specific industries, aimed to maintain control over labor costs and workplace policies. This dynamic led to significant conflicts and negotiations that shaped labor relations during that era.