They count on the $5,000 MAP grants to help pay for college.
About 75 students from Loyola University left early Thursday morning, and more than 300 DePaul students are also taking part in the rally.
"It's been a big help, throughout these 4 years in college -- almost 4 years, since I'll be graduating this year. Without it, I don't think I'd be able to be here," said Elena Suarez, Vice President, DePaul Student Government.
"I always wanted to go to school, and it really wouldn't have happened if I didn't have the assistance of the state of Illinois," said DePaul Grad Student Benjamin Levy.
Some of the students who are taking part in the rally are former grant recipients who want to show their support.
Lawmakers could vote today to direct the governor to use money already authorized for unspecified uses to fund the program.