I think it's designed that way because it wasn't originally seen as one country, more as a federation.
Even by the time of the civil war, Robert E Lee decided he was Virginian ahead of his national identity.
If you have a bunch of sovereign states, then you need some state-level evening out. If everyone is a citizen of one large state, you can just go proportional.
On top of this, it was never going to be easy to gradually move from one to the other with the issue of slavery looming large, so they didn't fix it. This was still a huge issue in 1848 when a lot of Europe was grappling with how to do a constitution.
Even by the time of the civil war, Robert E Lee decided he was Virginian ahead of his national identity.
If you have a bunch of sovereign states, then you need some state-level evening out. If everyone is a citizen of one large state, you can just go proportional.
On top of this, it was never going to be easy to gradually move from one to the other with the issue of slavery looming large, so they didn't fix it. This was still a huge issue in 1848 when a lot of Europe was grappling with how to do a constitution.
So it stayed broken and here we are.