Definitely try to find blueprints if you can. It’s not terribly hard to model from photos, but its not ideal. Wherever possible, use modifiers, e.g., array for pillars and stairs, deform for adjusting column tapering, etc. It’ll save you a lot of time later if you need adjust something!
Thanks, everyone for the kind words 
That’s very impressive.
Nice work indeed.
As for using separate objects for the whole thing, with Bmesh at least it wouldn’t be impossible to have it as a single solid piece, but sometimes it’s just a lot of easier to use objects instead (especially since in this case you wouldn’t be using any form of volume rendering either).
that’s awesome 
can you tell me the polycount? Number of faces used in this model?
@Ace Dragon, Thank you! I did consider using a single mesh but having multiple objects made is easy to separate it into different layers for better viewport performance.
@Slalamander, Thanks! The vertex count is 4,104,248. Face count is 3,939,702.
@deepsky Consider making a video play through of this model. Some screenshot doesn’t justify it’s beauty.
Great job, impressive.
@iamcreasy, Thanks! I was thinking of doing a video, but my computer renders too darn slow
@fred1209, Thank you!
Very impressive model. Are you going to add more detail to the statue on the center spire?
Thank you! I do plan on finishing the statue but my sculpting and retopologizing skills aren’t quite there yet 
Very well done!
Nice Job! Love the detail
Is there any chance I can get the file. I watched a movie called white house down and there was a bomb that exploded inside the capital. I just wanted to see if I could make something like it. Thanks for the read.