Do US Congressional Districts subdivide states or counties?

Question

I'm assuming it's states, but I'm not sure. Further clarifications, please?

Answer 1

Congressional districts in the United States all subdivided within the various states. A county may be located entirely within one congressional district or a within several. Generally, congressional districts are not divided by county in any way. Some states with limited population (Alaska, Wyoming, Vermont, etc.) only have one Representative for the entire state.