Is this on one ticket or two. If you are on separate tickets you do not have a 'connection' and are not protected on a later flight in case you miss the flight to Madrid. If this is on one ticket, then you'll be protected on a later flight, though I'm not sure if there will be one to Madrid that day.
If you are on two tickets, then this is a very tight connection and I would be concerned, because if you don't board the flight to Madrid then the rest of that ticket will automatically be cancelled. You'll have to buy a new flight to Madrid and anything else on that ticket. I would try to get on an earlier flight to Atlanta.