State has a law restricting marriage to one man and woman (20)
 
· Vermont*
· Connecticut*
· New Jersey*
· Arizona
· California
· Delaware
· Florida
· Hawaii
· Illinois
· Indiana
· Iowa
· Maine
· Maryland
· Minnesota
· New Hampshire*
· North Carolina
· Pennsylvania
· Washington
· West Virginia
· Wyoming

*Allows civil unions

State has no explicit law prohibiting same-sex marriage (3 states and D.C.)

· New Mexico
· New York
· Rhode Island
· District of Columbia

State has a constitutional amendment banning same-sex marriage
 
· Alabama
· Alaska
· Arkansas*
· Georgia*
· Kansas
· Kentucky
· Louisiana
· Michigan*
· Mississippi
· Missouri
· Montana
· Nebraska
· Nevada
· Ohio
· Oklahoma*
· Oregon
· Texas*
· Utah*
· Idaho*
· Virginia*
· Wisconsin*
· Alabama
· South Carolina*
· South Dakota*
· North Dakota*
· Tennessee
· Colorado

*Law or amendment has language that does, or may, affect other legal relationships, such as civil unions or domestic partnerships

Source: Human Rights Campaign, 2006