Depending on the time period in which you are referencing, labor unions had a mixed impact on working conditions. In the mid-1800s to late 1800s, labor unions weren’t very effective in accomplishing their goals. There were no laws that gave unions the right to exist. As a result, court decisions rarely supported union activities. Big business owners had all the power, and they rarely gave unions what they wanted.

As we entered the 1900s, things began to change. The Clayton Antitrust Act gave unions the right to exist. The Progressives were able to pass laws addressing the poor working conditions in factories. Worker compensation laws were passed along with health and safety regulations. Some workers got an eight-hour day, and child labor was banned. In the 1930s, the Wagner Act reinforced the idea that unions had the right to exist. The National Labor Relations Board was created to help workers resolve disputes. Eventually, the eight-hour day became the standard workday for workers in factories. During World War I and World War II, unions were able to improve conditions for workers. The government generally pressured companies to settle with unions in return for a no-strike pledge. We couldn't afford to have workers go on strike during a time of war. Thus in the 1900s, unions were more successful in improving conditions in factories than they were in the 1800s.