About 300 passengers on two trains that were stuck near Mendota boarded buses in Princeton for the final leg of their trip, said Amtrak spokesman Marc Magliari. They started arriving in downtown Chicago around 7 a.m. Tuesday and more were expected to arrive throughout the morning.
Also, a third train loaded with 217 people spent the night at a BNSF rail yard in Galesburg. They were taking buses for the final 150 miles to Chicago.
The trains - The Southwest Chief from Los Angeles, the Illinois Zephyr from Quincy and the California Zephyr from San Francisco - got stuck after 3 p.m. Monday in blowing, drifting snow and ice that Magliari said made the tracks impassable.
Several passengers speaking to news outlets by cellphone said conditions on the trains deteriorated and that they went long periods without food.
"The conditions is cold, we're wearing coats. And my husband is a diabetic. He hasn't had any food all day," passenger Laurette Mosley told ABC News by cellphone. "The bathrooms are flooded. The sinks are full with water and the toilets are flooded." Mosley was en route from California to Chicago to attend her mother's funeral.
Magliari said train crews handed out food and prepared for any medical issues, though he said there were none. He said the bathrooms on board the trains were working.
Amtrak canceled nearly two dozen trains in Illinois on Tuesday because of the cold and lingering snow from a weekend storm that dumped more than a foot of snow in some areas of Illinois.
Magliari said crews were clearing tracks and hoped to resume operations Wednesday.
ABC News and the Associated Press contributed to this report.