Hi @Nems, I've moved your post into Ask Damien, since it's not a class-related matter.
Of course it cropped! Those dimensions (like all web dimensions) are much smaller than full resolution.
So the issue is not "whether it crops". The issue is all about you controlling the crop.
So, when you said ...
How did you enter them, exactly?
If you entered them in the Image Size or Canvas Size dialogs, that's bad. The correct way to do it is with your Crop Tool.