Maybe it's just hindsight bias but I was thinking about the major wars the US has been involved in over the past century and most of them seem to have started from an "accident" at very convenient times. The sinking of the Maine and Lusitania. Pearl Harbor and 9/11 (this one might be too recent to talk about) Is this all just one big coincidence? Or am I just seeing things different from a 21st century education of the events.
You're looking at it in a very superficial way.
The sinking of the Lusitania happened a full two years before the entry of the war, being one of many reasons which led to the United States entering the First World War. The First World War did not start for the United States with the sinking of the Lusitania 1915 but rather with the declaration of war in 1917.
Pearl Harbor is not an 'accident' at a 'very convenient time' but a highly timed, well-thought out and highly professional military raid at a US naval base to knock the US Pacific Fleet out of the game as the Japanese expanded over the Pacific and South-East Asia.
You have only mention four examples, three of which we can speak of in this sub, but there are plenty of other American wars that did not start out this way and arguably one of the largest and most important wars in American history, the American Civil War, did not start 'in that way'.