The United States is home to about 7 percent of all Catholics in the world. As of 2010, an estimated 23 percent of U.S. adults and 24 percent of the total U.S. population are Catholic. The U.S. Catholic population has lost more members than it has gained from denominational switching.
Definition of civil union. : the legal status that ensures to same-sex couples specified rights and responsibilities of married couples.
If you are referring to the United States as the 'union' then the answer to that would be Hawaii and Alaska. If you are referring to the Union that I am thinking of, then that question is nonsensical. 'During the Civil War, the Union was a name used to refer to the federal government of the United States, which was supported by the 20 free states and five border slave states.