Alaska Airlines said on Wednesday it had completed its $1.9 billion acquisition of Hawaiian Airlines after reaching an agreement with the U.S. Department of Transportation.

Alaska Airlines closed its $1 billion purchase of Hawaiian Airlines on Wednesday, a day after the federal government removed the last major regulatory obstacle to the deal. Alaska will also assume about $900 million in Hawaiian debt.

Things are about to change for Alaska and Hawaiian Airlines customers. On Wednesday, Alaska Airlines acquired Hawaiian Airlines in a historic merger. The acquisition is the largest merger between U.S.