Civil unions are different from civil marriage and that difference has protections, provision of insurance for families, and means-tested programs like Medicaid.
No. Civil unions are not recognized as marriages in West Virginia.
Yes, civil unions and even some domestic partnerships (the ones that are substantially equivalent to marriage) are recognized as legal marriages in the District of Columbia.
No. Same-sex marriages, civil unions and domestic partnerships are not legally recognized in Vanuatu.
Civil unions are not legally called "marriages" and partners in a civil union are not legally called "spouses." That is the only difference between a civil union and a legal marriage.
No. Although civil unions are not legally defined in Iowa, same-sex marriages are legal in Iowa.
Yes, New Hampshire recognizes out-of-state (as well as in-state) civil unions as legal marriages.
Civil Unions were invented as an alternative to marriage for same-sex couples. In the United States, all marriages are entered into according to state laws. The federal government does not issue marriage licenses, register marriages, or issue marriage certificates. Since civil unions are analogous to marriages, the same holds true for them.
No. A civil union and legal marriage are two different things. If you perform a civil union, then you end up with a civil union, not a same-sex marriage. The only exception is in the states that used to permit only civil unions, but now allow same-sex marriages. In some of those states, existing civil unions were automatically converted to marriages. In at least one other state (Vermont), civil unions remained civil unions and no new civil unions were permitted.
There has never been a law allowing same sex marriages in the UK. Recently Civil Unions have been introduced which are in most ways similar to marriages.
Polygamy, Bigamy, and sometimes civil unions
No. Some states recognize civil unions as civil unions, some as marriages and some as domestic partnerships. Many states do not recognize them at all.
Yes. Same-sex marriage is legal in Massachusetts and out-of-state civil unions are recognized as legal marriages.