Members of the "Tax Dodgers" -- a group that satirizes corporations that evade paying taxes -- perform for the crowd in Union Square. Jeremy B. White

A coalition of interest groups encompassing immigration advocates, organized labor groups and members of Occupy Wall Street gathered in Union Square on Tuesday afternoon for a May Day rally.

If there was a common theme uniting the participants, it was a sense that American society is exploiting the vulnerable. Speakers touched on topics ranging from organized labor movements in Ecuador and the Philippines to U.S. immigration law to the New York Police Department's controversial stop and frisk tactic. Two large banners hung behind the stage, one displaying the Occupy Wall Street mantra We are the 99 percent and the other the phrase Equal Rights For All Workers: Stop the Raids and Deportations.

You guys look like America, city council member Jumaane Williams told the crowd. The poor people are tired. The middle class is tired. The workers are rising up and we're tired, and we're going to sustain this agitation until we get some relief, Williams continued, setting off a chant of Agitate! Agitate!

Protesters waved signs bearing the numbers of various labor union shops, and speakers included representatives from the United Auto Workers and the Transit Workers unions. Organized labor has allied itself with the Occupy Wall Street movement the leaderless movement's early days.

We stand in unity, said Janella Hinds, secretary-treasurer of the New York City Central Labor Council. We continue to fight for fair working contracts, for just working conditions, for fair pay for all of our people.

Immigration also played a prominent role. Many of the speakers addressed the crowd in Spanish, and the rights of immigrant workers was a recurring topic. An undocumented student called on New York lawmakers to pass the state's DREAM Act -- a bill that would allow undocumented students to pay in-state tuition at state universities -- and a speaker drew boos and hisses from the crowd when she mentioned the controversial Arizona immigration law that the Supreme Court is considering this week.

The rally featured some musical acts. Tom Morello, the former guitarist of renowned rap-rock band Rage Against the Machine, was joined onstage by dozens of other guitarists as he rallied the crowd with a song titled Worldwide Rebel Wongs. A jazz band played a set on behalf of the New York chapter of the American Federation of Musicians. Other artists included Dan Deacon, the rap collective Das Racist and the rapper Immortal Technique.

Occupy, Immortal Technique, whose real name is Felipe Andres Coronel, told the crowd. They said to me that we're back. My message to them was, we never left.

After the musicians performed, a group of Occupy Wall Street representatives told the crowd that Wall Street is the symbol of the colonization of the 99 percent by the one percent before demonstrating some nonviolent techniques for resisting the police.

Protesters then began marching downtown toward Union Square. Check back with IBTimes for updates throughout the evening.