AA 4191 then UA 5191 at O'Hare
Rochester (ROC) → Chicago → Lancaster
Timetable, Chicago time
12:37AA 4191 from Rochester (ROC) at the gate
08:50UA 5191 to Lancaster leaves the gate
20 h 13 apart on the timetable, overnight
UA 5191 leaves 20 h 13 after AA 4191 arrives on the timetable: more than half a day, so not a connection we count.