What are the steps involved in Domestic to International connection at Dallas/Fort Worth?

Question

I have a flight from Greensboro, NC (USA) to Melbourne (Australia) coming soon and this is my first time leaving USA. I am not a US passport holder, just have a visit visa. The legs look like this:

1. Greensboro, NC -> Dallas/Fort Worth Airport, TX (layover: 59 minutes)
2. Dallas, TX -> Sydney (Australia), and so on.

Given the layover time is less than one hour, I was concerned and asked my travel agent to change it. They are asking for a quite a bit of money and said it is still over the the minimum connection time so a 'legal' connection. I am not overly confident about their remarks.

Can anyone tell me exactly what steps are involved in a outbound domestic to international connection in USA?

Specifically, do I need to:

1. Collect my luggage at Dallas?
2. Depart domestic terminal, go to international terminal and re-check the luggage?
3. Again go through the Immigration and Security to board the international flight?

I have a bad experience when I was coming to USA due to a short layover time. The first flight was delayed from Melbourne and I missed the connecting flight due to wrong instructions from airport staff. I was put on standby and AA gave me a flight after 18 hours.

Disclaimer: I have searched quite a bit and mostly found questions involving international to domestic transfer, which does not apply to me.

Answer 1

Assuming that you have booked a single ticket, you will not need to collect your luggage, recheck luggage, enter or exit the terminal, or go through security or immigration. You will simply need to get yourself to the gate for your next flight before boarding closes. When you check your bags in Greensboro, simply confirm that they are "checked through" to your final destination of Melbourne (you will likely need to pick them up in Sydney and take them through Customs there, as that is your first port of arrival in Australia).

If this does involve changing terminals (which is, according to Michael Hampton, inevitable), you can do that with the Skylink train inside security, which runs every two minutes. The ride between the farthest points takes nine minutes.

This should be doable if your flight isn't significantly delayed, but doesn't leave a ton of time if things go wrong. If you do find yourself running late, it's worth informing the airline staff of the situation, as they may be able to facilitate a cart ride to get you to the gate faster, or at least inform them that you're on the way.

Answer 2

1. Collect my luggage at Dallas?

No you will not. Almost certainly, your luggage will be checked through to Melbourne, or at least to Sydney. You won't need to collect it in Dallas.

2. Depart domestic terminal, go to international terminal and re-check the luggage?

No, as noted, you won't have to recheck your luggage. Your flights will not be at the same terminal. (Thanks to Michael Hampton for this information.) I don't know DFW well enough to know how much time you will need for the transfer.

3. Again go through the immigration and security to board the international flight?

No, there is no immigration control when leaving the United States. You normally should not have to go through the security check again, because the train linking the terminals connects the secured areas with one another; the train is said to be "inside security" (see Zach Lipton's answer for the link). If for some reason you do have to clear security again, the airline should be able to expedite your transfer if it is necessary.