About 300 passengers on two trains that were stuck near Mendota, about 80 miles from Chicago, boarded buses in Princeton for the final leg of their trip, said Amtrak spokesman Marc Magliari. They were expected to arrive midmorning.
A third train loaded with 217 people spent the night at a BNSF rail yard in Galesburg; they were expected to take buses or another form of transport 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 the San Francisco Bay area - got stuck after 3 p.m. Monday in blowing, drifting snow and ice that Magliari said made the tracks impassable.
Passengers spent the night sleeping and eating while emergency workers were on standby. Train crews handed out food and prepared for any medical issues, but authorities said there were none.
"There was no good reason to take people out of warm trains ... into the cold," he said. "We sheltered them in place."
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.