The workers were protesting at the South Carolina Medical College Hospital demanding wage increases and union recognition.
Several plan to quiz Perez on his stewardship of the Justice Department's Civil Rights Division, which he now heads.
The crowd demanded Congress pass legislation providing a path to citizenship and other legal rights for the estimated 11 million undocumented people in the U.S.
An assassin's bullet felled the Rev. Martin Luther King, Jr. on April 4, 1968. King had come to Memphis to support a strike by the city's sanitation workers.
Service Employees Secretary-Treasurer Eliseo Medina told President Obama of SEIU's all-out commitment to immigration reform.
Organizing Canton could be a stepping-stone to organizing the South's growing auto industry. "This particular campaign is beneficial both for the nation and for the world."
The labor movement is celebrating its ties to the civil rights movement here this weekend as the AFL-CIO gathers to honor Dr. Martin Luther King Jr.
On January 15, 1915 in Chicago there was a big march on City Hall by some 1,500 jobless and hungry people demanding relief.
Activists taking part included House Minority Leader Nancy Pelosi, Latino civil rights figure Cesar Chavez, and then-presidential candidate and civil rights defender Jesse Jackson.
Thurgood Marshall was sworn in as Supreme Court justice, making him the first African American in history to hold that position.