That is incorrect. I entered the US Customs Academy at the FLETC in Glynco, GA in October 2003 while DHS was being created and graduated as a US Customs Inspector under the Department of Treasury. The course was extended to include immigration law as the two agencies were merged under the DHS unbrella as Customs and Border Protection.
While I was at the academy, there was a lot of infighting and bickering between the 2 agencies. It got pretty silly and even the FBI got involved. They got their back up when one of the names proposed for the new agency was put forward as The Bureau of Customs and Immigration. They didn’t want anyone else using the name Bureau.
It was resolved before I graduated in February 2004 and a short time later, we were issued new badges and credentials and became CBP Officers under DHS.