I'm sure you picked good keywords and you probably included lots of unique content in your article. From some of my experience with researching posting articles and getting them indexed it is easier and faster to get Google to index your site if you write in the natural style that you talk. A lot of people make the mistake of trying to be too much like a book author editor and not be unique.
Try writing in different style and test the progress of the articles.
It could be you choose a good keyword. Most likely this is the case.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.