UA 4301 then AA 2645 at Houston
Lubbock → Houston → Chicago
Timetable, Houston time
18:41UA 4301 from Lubbock at the gate
14:32AA 2645 to Chicago leaves the gate
19 h 51 apart on the timetable, overnight
AA 2645 leaves 19 h 51 after UA 4301 arrives on the timetable: more than half a day, so not a connection we count.