"When the president shows up, it shows ultimate national seriousness," said Jackson, a Chicago resident. He also called for the U.S. Department of Homeland Security to help patrol the streets of Chicago.

Gun violence in Chicago has been in the national spotlight over the past year, with 506 murders in 2012, an increase of 17 percent from the previous year. As of Thursday, there were 42 homicides and 157 shootings so far this year, according to Chicago police.

The issue received new urgency with the killing this week of 15-year-old Hadiya Pendleton, an honors student who performed with her high school band at Obama's inauguration on January 21.

News of her death near Obama's old home in the Kenwood neighborhood came before the U.S. Senate Judiciary Committee began hearings on gun control on Wednesday. Obama's spokesman, Jay Carney, has said the Obamas are praying for Pendleton's family.

Anita Crittenden, who lost a nephew to gun violence last year, said Obama, by coming to Chicago, would "get the leaders to think and step up and make some changes."

A petition posted on the White House's "We the People" website calls for Obama and his family to attend Pendleton's funeral on February 9. The petition must have at least 100,000 signatures to receive an official response from the White House.

Jackson led nearly 150 people on a march from Martin Luther King Jr. College Prep High School, where Pendleton was a student, to the park where she died a few blocks away.

"My greatest fear about the gun violence in Chicago is that we're adjusting to it," he said.

Police said Pendleton was shot to death on Tuesday as she and her friends were shielding themselves from rain under a canopy in the park. Police have called it a case of mistaken identity and are offering a $40,000 award for information leading to her killer.

Emanuel announced plans on Thursday to take 200 police officers now serving in administrative positions and deploy them on the streets.

"Hadiya wanted to make a difference in the world," said Shatira Wilks, a spokeswoman for the family, and cousin of Cleopatra Cowley, Pendleton's mother. "It's unfortunate that it would be like this, but we still hope that this can make a difference."

Not everyone participating in the march agreed that Obama should come home. Matthew McGill said the president should address the violence issue, but need not single out Chicago, "because what you see in Chicago happens in other cities as well."

(Editing by Mary Wisniewski and Peter Cooney)