I will be arriving the US from Nigeria in November on Delta Flight enroute Washington Dulles via Atlanta. I'll be travelling alone with my 1yr old son. Our layover on the outbound flight is 1hr 40mins. I am new to the ATL airport. I am particularly concerned about the layover, will it be sufficient for me to carry my son along and go through customs, retrieve and recheck our luggage and still make the connecting flight to IAD? I have heard that ATL airport is quite huge and busy. The cost of changing the connecting to a late one is too expensive.