In the USA, what is the purpose of a Union? Does the system work?

Sometimes they work well and sometimes they don't. Kind of depends on who's running them. I think the "Union" system is becoming outdated but a lot of people get pensions because of Unions. So there is good and bad.

The purpose of a union is basically to protect the "rights" of an employee and make sure that things such as wages, working hours, and contracts are kept at a fair level. Unions sometimes take advantage of companies; however, and put bad workers in place.

Like Rooster said.

Here's some ways to tell that unions are becoming corrupt and outdated:

1 - When legislation is passed to give people a CHOICE to joining unions or not - unions claim it is "union busting".

2 - Unions want legislation that, when employees petition to vote whether or not to become a "union shop" - that means ALL the employees at that company are automatically union members.  In other words, those employees just wanted a chance for everyone to vote - they weren't asking (yet) to be IN the union.  But the union takes a stance that just wanting to raise the question, means that everyone wants to be in the union.

3 - When people forced to be in unions have been given the choice of leaving (by #1) ... Many of them do so.

Keep this in mind. If you don't join and you need them the Union will NOT represent you in any legal matter or when you're fired or demoted or written up.

Not a position as much as an observation to help Corey The Goofyhawk to pursue his interest in the subject of his question:

"Effective labor unions are still by far the most powerful force in society for the protection of the laborer's rights and the improvement of his or her condition. No amount of employee benevolence, no diffusion of a sympathetic attitude on the part of the public, no increase in beneficial legislation can adequately supply for the lack of organization among the workers themselves."

"We should be particularly concerned about the weakening of labor organizations, because we are not likely to have a free and democratic society without a free and democratic labor movement. Trying to have economic democracy without unions is like trying to have political democracy without political parties."

"In stressing the need for strong and effective labor unions and opposing efforts to thwart labor's right to organize, the Pastoral is not suggesting that unions in the United States are above criticism. Moreover, the Pastoral is not siding against management, much less pitting labor against management. To the contrary, it explicitly states that workers have obligations to their employers and that trade unions and their management counterparts jointly ' have duties to society as a whole.' The Pastoral, calling for 'an imaginative vision of the future that can help shape economic arrangements in critical new ways' strongly emphasizes the representative and coordinating role of organixed labor and management, jointly assisted by government, in developing new forms of bona fide partnership for the public good." In fact, given new challenges to American productivity from globalization, argued Higgins, such a new sense of partnerhsip between workers and management may be crucial to remain competitive. It is a mistake, he argued, to see labor and management as, necessarily, always at arms' length or inherently always adversarial.

americamagazine.org/content/all-things/remembering-msgr-geor