"While the Federal government has not done what they are supposed to...American people have opened their hearts," Cruz said.
But Cruz also warned the group that the Puerto Rico has a long way to go in its recovery.
Nearly seven months after the hurricane devastated the island, hundreds of thousands remain without electricity, clean water and other necessities.
Sarah Quinn brought her 76-year-old mother-in-law to live in Oak Brook because she has no power back home in Puerto Rico. Other relatives remain on the island without electricity.
Quinn said she hopes the Cruz can keep attention focused on Puerto Rico.
"There are still hundreds of thousands of people that don't have a permanent roof over their heads....don't have a temporary roof over their head," said Illinois Representative Luis Gutierrez.
The situation has the potential to get worse. Cruz said the next hurricane season begins in a couple months, and Puerto Rico is far from prepared for the storms.
"It doesn't have to be a category five... could be a category one, and we're going to be again back to ground zero" Cruz said.
Cruz will return to Chicago later this week to speak before the City Club downtown.