U.S. senator from Ohio?

It would certainly be clearer to say John Glenn was the Senator for Ohio, which is what he was. Not knowing your source for your quotation, it is difficult to comment on why "from" was used.

Each state in the US sends two Senators to the US Senate. Most, but not all, of the separate states also have a state senate and state senators. When a source like yours says a person was a US senator, then you know this refers to the national Senate rather than one of the state government bodies. A senator in a state government would usually be designated, "Senator in the Ohio state le

U.S. senator from Ohio = a senator of national level, not a senator of state(Ohio) level (of course the senator was from Ohio)?

Yes. National level. Otherwise he would be a state senator, or, more specifically, an Ohio state senator. He would then not be described as from Ohio, but from District 101, or from District 324, or from

It would certainly be clearer to say John Glenn was the Senator for Ohio, which is what he was. Although in some sense Glenn could be described as a senator "for" Ohio, U.S. senators are usually referee to as "the senator from a particular state" -- perhaps because that state sends the senator to Washington D.C.

And, as Spides and Jim have alr

Thanks for the clarification - Glenn's own website states: Astronaut Glenn now became Senator Glenn. In this new career, he represented Ohio.

Although in some sense Glenn could be described as a senator "for" Ohio, U.S. senators are usually refered to as "the senator from a particular state" -- perhaps because that state sends the senator to Washington D.C.

Yes, exactly. In the odd speech of the U.S. Senate, you will hear phrases like "The distinguished gentleman from Virginia