What might the "Merchant Jack" be?
Diane, the dressing overall was done on Good Friday, April 5th. That is an old custom that is done on festive occasions. One story is that it was done on Titanic by way of putting on a show instead of opening the ship for public inspection as was often done.
I'm damned if I can see the US flag in any photos and I've got quite a few. For me, photos beat speculation any day. I wouldn't trust Ken Marschall's drawings. I've got one of his showing Lusitania wearing the Union Flag. That was illegal because the Union Flag was reserved for the Royal Navy and the Royal Yacht.
No one in this thread said anyone should use Marschall's paintings as proof. They were simply stating why he (properly) paints the flag he does. I'm not sure why you have such a hard-on for the guy and are so bitter about the Stars and Stripes being flown, but it is not speculation, it is 100% historically accurate. Not for nothing, but contemporary maritime practices, witnesses, photographs, articles, and modern experts deserve credence over your personal insecurities and obvious disgust for the reality of the flag situation on the Titanic.