Trump also did not even inform the armed services or foreign affairs committees. He spoke to FOX before he spoke to Congress. It is not clear if he's done or if we just declared war. His public statement that the US will now be majorly involved in Venezuelan oil is both very telling and very mysterious. How the hell are we going to assert power over their industry without foisting a new, friendlier government?
We definitely didn't declare war if Congress isn't in session or otherwise able to vote.