It was more about kidnapping British seamen who were pretending to be American, which it was easy to do in the days before birth certificates. There had been a massive increase in the American merchant marine, taking New World goods to Europe, as the Royal Navy had made it difficult for these goods to be transported in French and allied ships. Many British seaman took advantage of this to join American ships. The British view of this was that they were still British and liable to impressment (a loathsome system, but nevertheless part of British law).

The USA also complained about the imposition of the blockade, but compare this with British blockade runners running into Confederate ports in the American Civil War.

I personally think of this war as an attempted American land grab, at a time when Britain was heavily involved in another war. And as for the chaps waiting at Bladensburg - on your marks, get set ...