LH, my post here is coming in very late after yours about the Lusitania. I just thought you might be interested to know that I was reading an article some time last year (can't remember when right now, but i cut out the piece and kept it somewhere). There has always been some controversy over whether or not the Lusitania was merely a civilian liner. Some claimed it was being used to transport munitions and the Germans knew this somehow. In support of that claim was the fact it sank so rapidly after two large explosions tore open its hull (one might have been the torpedo, the other munitions exploding). It sank in about 20 minutes if I'm not mistaken. There was no real proof though until last year when a salvage team went down and among other things they found thousands upon thousands of rounds of ammunition, some of it still boxed up. They brought some samples to the surface. The ammunition turned out to be .303 calibre made by the Remington company. This is significant as Remington was (and is?) a US arms manufacturer, but the .303 round was not popular in the USA (I don't think it was used there at all, actually. There was a 30-30 but that was a totally different round and not interchangeable with the .303). On the other hand the .303 was the standard round of the British army from about 1890 (Lee Metford rifles and later Lee Enfield) up to the 50s or 60s when the NATO 7.62mm took over.
Since a lot of the ammunition would have blown up in the explosions that sank the liner, the recent find is probably only the tip of the original iceberg, so to speak.
This would suggest that the Lusitania was carrying ammunition from the USA to Britain. The US and British authorities must have been aware of the risk to the civilian passengers involved in placing munitions on a civilian liner. They deliberately placed munitions among civilians on a civilian liner as a kind of camouflage - knowing the Germans would definitely have torpedoed any merchant ships thought to be carrying munitions.
The fact it's taken 80 years or more for this story to be known in its entirety is a good reminder of why we should bear in mind "the first casualty in any war is the truth"