Heading to Johannesburg, SA from Atlanta - First time International Flier - Need some Help

You don't go through customs in Chicago, just a few looks at your passport and do you have a visa? But I think 51 minutes in Atlanta I would question. If this is all in one ticket, Delta should have your connection guaranteed. But guaranteed only means that if you miss the connection, Delta will get you on the next day's flight to Johannesburg. So I would like to see longer connection time in Atlanta. There are several terminals connected by underground shuttle train, and sprinting might not be enough.

Not knowing when your trip is,I picked a weekday in May and Delta shows a 64 minute layover in ATL as the shortest time. Have you already purchased the ticket? If not I would chose an earlier flight from ORD to have a bit of a cushion.

If you already have the ticket I would call Delta and see if they would put you on an earlier flight form ORD and waive the change fees. If you miss the flight from ATL it looks like it would be 24 hours before the next one.

It definitely sounds a bit tight -- too tight for my comfort level. If you've not purchased tickets yet try to get an earlier flight from Chicago. Hopefully you'll be able to get both legs on one ticket if case there is a missed connection. In all probability you will land at one of the domestic terminals and depart from the international terminal. That means taking the "plane train" to the departure terminal but it's really not a big deal -- just time consuming. The Atlanta airport has a pretty good web site with lots of information, maps, and etc. You might want to check it out.

You will get both boarding passes at once. I would show up 1-1/2 hours before flight from O'Hare as this is a domestic segment. Not sure I would check a bag with such a tight connection.

Do yourself a favor and change to the 3:06 Delta flight to Atlanta.
At least today, flights from Chicago land at Terminal B and you have to transfer to International Terminal F. So that means taking the train. I don't know about any additional security at Terminal F.

I called Expedia, who the trip is booked through. To simply change flights, they want $775, that isn't going to happen, so it looks like I will be praying for an early arrival, good weather, and the train to carry me quickly there.

One more reason to book direct with the airlines.

First, customs, immigration (passport control) and security are three different things. In the US we often say "customs" to mean all three, but it's important to understand the difference and to use the correct terms to avoid confusion (particularly in other countries, where they use the terms correctly).

Second, while I understand wanting to know what's involved before you get to and through the airports, remember that you won't be allowed to skip any necessary steps. And, for various reasons, the exact steps and procedures can change. Be prepared to go with the flow.

You should check in for your flights on line or on the Delta App. Check in opens 24 hours before the flight, and you should get an e-mail notifying you (if you have the app, it will also notify you). Often these days, you can get the boarding passes on your phone, and/or can get them e-mailed to you as PDF's that you can print. But sometimes you have to wait to get to the airport to get your boarding passes; again, go with the flow on this. When you get your boarding passes, you should get both the one for ORD to ATL and the one for ATL to JNB.

At the airport, you will get your boarding passes (if you do not have them already) and check your luggage. It should be tagged JNB (make sure of this); as long as it is, you will not see your checked bags until you get to Johannesburg. For your carry-on bag, in addition to valuables and several days of clothes, make sure you have any rechargeable batteries (Delta is quite strict on not letting these in checked luggage, for risk of fire). You then go through security to your gate for your ATL-bound flight. Since this is a domestic flight, there is no customs or passport control at this stage.

In Atlanta, you get off your first flight and find your second one. If it's more than 1 or two concourses away, take the Plane Train (like a subway); if it's close you can walk just as fast. I don't think you will have to go through security in ATL, but I'm not sure. You will not go through customs or passport control (unlike most other countries, the US has no passport control on departure). However, the airline may want to see your passport, to make sure you have it (they get a HUGE fine if you are refused entry to another country - in addition to being responsible for flying you back to the US at their expense).

On arrival in JNB, you will go through passport control, then pick up any checked luggage, then go through customs. I haven't flown to South Africa, so I don't know more about their procedures.

On your return to the US, you will get both boarding passes in Johannesburg. If you are checking luggage, make sure it says ORD. You will go through security and passport control on the way to your flight. You will only deal with customs if you have something special, like a tax refund.

For all flights to the US, you go through immigration and customs at your first US airport, regardless of your final destination. So, on arrival in Atlanta, you will go through passport control, then pick up all checked luggage, then go through customs. This can be fast or slow, depending on how many other international flights are arriving and how many agents are on duty. After customs, there is a "baggage recheck" area; if you have checked luggage, deposit it here (the ORD tags will get it to the right flight, hopefully). You then go through security (since you've left the secure area) on the way to your next flight. You are now done with the "formalities," and your ATL to ORD flight is like any other domestic flight.

If for any reason you're lost or confused in an airport, don't hesitate to ask for help right away.

I called Expedia, who the trip is booked through. To simply change flights, they want $775, that isn't going to happen, so it looks like I will be praying for an early arrival, good weather, and the train to carry me quickly there.

Divine intervention is definitely needed, but as Delta lists it as an itinerary on their site, they seem to think it can be done. They also show several other choices, all at the same price, that do not have the heart attack close connection.
Expedia et al are great for research, but booking with the airline is best, especially an international trip involving a connection.

This is an instance where you should have in your carry on whatever you might need if you have to spend the night in Atlanta. Also it might be smart, if you are staying in a hotel in Johannesburg, to have a second reservation for just the first night. Then you can cancel it if you miss your plane without having to pay for a night, and lose the reservation for the other nights by not showing up for the first night.

I checked if KLM might work as an alternate, and although the flight to AMS leaves Atlanta late enough, the flight from AMS to JNB has already left for the day before the AMS flight arrives from Atlanta.

It is always helpful to pull up the website of any airport you are bound for, to get an idea of the layout. I print out terminal maps but the more electronically adept may be able to use a smart phone to get around.