Senator Dick Durbin is calling the decision "unacceptable" and is pushing for a meeting between members of the Illinois congressional delegation and the FEMA administrator.
Gov. Pat Quinn, who surveyed the damage, released a statement Sunday calling the denial extremely disappointing.
He also expressed support for Durbin's efforts to appeal the decision.
"After personally surveying the damage and talking to many residents who lost their homes, I firmly believe federal assistance is crucial to help them begin the recovery process," Quinn said in the statement.