No Atlanta to Dallas? Brownsville is pretty much the end of the line, from what I experienced last month. One problematic aircraft, and you're spending another night in Scorpion City.
And hell, I know United sends an Embraer ER145 to "Dheltastan" via that loathsome Gate B84 at Houston. Hope you got the deal of century, or whatever mission-critical job worked right on time for those plans.
This was about 9 years ago, so schedules have changed since. I flew CO from ATL to IAH, then connected into Brownsville to meet a guy at the border to pickup a package (bound for Singapore). It was Spring Break season so flights in and out of Brownsville weren't an issue because of all the kids going down to South Padre Island. Flew AA from Brownsville to SFO, connecting at their hub in DFW that afternoon. Then Singapore Airlines ex SFO.
I got to fly business the whole way, plus got paid double my hourly rate at the time multiplied by the 50 something hour round trip, so it worked out pretty well for me. Plus on the flight to Brownsville I was surrounded by about 9 girls on spring break who were convinced that I was some kind of international mystery man after they asked what I was doing, so that wasn't bad at all.
Before anyone says I was a drug mule or any further such speculation, here is the story.
Our largest customer had a line down at their Singapore factory. When a production line goes down for big companies, it costs lots of money. In this case, $320,000.00 per hour. This customer makes the very tiny silicone chips that make up computer microchips. The company is the largest of it's kind and their product can be found in 70% of all electronics around the world.
So their production line in Singapore was down, and the chips are all made in Mexico at 3 different plants. All they needed to continue prodution was about 30,000 chips, fitting in 1 box, about 7 lbs. So in order to avoid delay by an airline or FedEx, a company like mine will do what's called a "hand carry", and have an actual person take the parts with them as baggage, to ensure the product gets there with no issues. I met a contact with the company at the Mexican border, and took the box with me to Singapore, where I handed it to people waiting for me at the airport.
I did the same thing for an automotive company for parts going from NC to Budapest last month, but that was only 2 flights.