Civil Unions in Vermont
Vermont was responsible for establishing the concept of civil unions and introduced the first legislation providing it as an option for same-sex couples. In 1999 the Hawaiian Supreme Court refused to recognize same-sex marriages. That same year the Vermont Supreme Court handed down a decision stating that same-sex couples should be afforded the same benefits and protections that heterosexual couples receive under state law. The following year the state legislature passed a bill authorizing same-sex couples to enter into a "civil union." Although not termed marriage the civil unions shared many features.
Applicants could apply with the town clerk for a license just as with a marriage license, and a ceremony would be performed by anyone authorized to perform marriages under state law. Vermont's law was a landmark event in the fight over same-sex marriage and several other states introduced laws similar to Vermont's.
Eventually, however, Vermont decided to do away with civil unions and in 2009 approved same-sex marriage. Civil unions are no longer available in Vermont, though civil unions created prior to 2009 are still acknowledged by the state.
Civil Unions v. Marriage
Civil unions share many of the rights and responsibilities that exist in a marriage including inheritance rights, bereavement leave, mutual rights to employment benefits such as insurance, automatic designation as next-of-kin, joint ownership of property and community property rights, joint tax filing, joint parental rights, the right not to testify against your partner, and the right to seek financial support or alimony upon dissolution of the relationship.
Differences were more important prior to the 2015 Obergefell v. Hodges decision by the Supreme Court, making same-sex marriage available in every state. Since this decision marriage is available for same-sex couples and many of the reasons for making civil unions available are moot. Differences between federal and state law, or differences in laws between states that used to be the source of many distinctions between the way marriages and civil unions were treated have been eliminated by the Obergefell decision, which required that states provide equal protection to same-sex couples.
In fact, it remains to be seen whether civil unions remain available given the new availability of marriage for all. Some civil unions may persist from the period prior to the legalization of same-sex marriage but it is uncertain why a civil union might be necessary moving forward. They do, however, provide insight on how the same-sex marriage movement was successful securing rights for same-sex couples.