Its probably a good article but I found it extremely longwinded and I got bored after page 2 and stopped reading. I believe the short explanation is that when the original States (about 15 of them I think - all in the East) were trying to unite, there was a bun-fight over where the new capital should be - Philadelphia in Pennsylvania had been the old capital. It was somehow agreed that the new capital shouldn't be in any one State, to stop any one state becoming too powerful. Maryland, Delaware and Virginia each donated a bit of land for the new capital, which is why is it where it is - on the border between all three of them.