AA 9908 then UA 1811 at O'Hare
Milwaukee → Chicago → San Francisco
Timetable, Chicago time
13:50AA 9908 from Milwaukee at the gate
13:30UA 1811 to San Francisco leaves the gate
23 h 40 apart on the timetable, overnight
UA 1811 leaves 23 h 40 after AA 9908 arrives on the timetable: more than half a day, so not a connection we count.