He was the only Senator to vote against his party.

He is the only senator to have represented three different states.

Now he's the only senator courageous enough to tell the truth.

He remains the only black senator ever to win re-election.

In 1861 he was the only southern senator to remain loyal to the Union.

During his time in the Senate, he was the only senator to always vote no on a woman's right to vote.

During much of his Senate career, he was the only Jewish senator as well.

He's not the only senator interested in that target.

He said that a year ago he was the only senator calling for a withdrawal.

He was the only senator to vote against a resolution authorizing Lincoln to use "the entire resources of the government" for the war.