When did the train he was travelling on arrive in Chicago?

The train I was traveling on was already half an hour late. I had planned to arrive in Chicago at 7:00 in time to catch the 7:50 train to St. Louis, but there was no hope of that now. I explained the situation to the conductor who advised me to get off before Union Station and take a taxi. When the time came, he even helped me with my language. He wished mea good luck as I jumped off, and a few minutes later I was going towards the Union Station in a taxi. It was almost 7:50 when we stopped outside the station, I paid the driver quickly, carried my bags and hurried inside.
    "The St. Louis train....’?" was all I had time to say to the first porter I saw. You can imagine my disappointment when he pointed to a train that was just moving out of the station.