Because marriage was originally/is a religious rite practiced in Judaism, Christianity, and Islam. The religious rite requires a heterosexual couple, as all three religions consider (in most sects) homosexuality a sin. The push for same-sex marriage comes primarily for a desire for the homosexual partnership to have the same LEGAL rights as a heterosexual partnership, but because of the use of the term 'same-sex marriage' the followers of said religions fight to prevent legal sanctioning of the partnership, in many cases only to protect sanctity of their ritual, and not because they really think that it should be illegal for homosexual relationships to exist, as the greater part of the population is rather tolerant of homosexual partnerships.
These are the US states that have legalized same-sex marriage:
These states have banned same-sex marriage:
As of November 19, 2014, same-sex marriage is legal in 35 US states and not legal in 15 US states. The reason why same-sex marriage continues to be banned in the 15 states where it is not legal is because those states have not yet had their bans on same-sex marriage struck down as unconstitutional yet, nor has the United States Supreme Court ruled definitively on whether the Constitution permits individual states to deny basic civil rights to citizens based on their gender or sexual orientation.
If by "illegal" you mean "against the law," then none. In none of the fifty states is same-sex marriage considered a crime. However, in some US states, same-sex marriage is not legal in the sense of "not legally recognized." Please see the attached related question for a numbered list of US states that have banned same-sex marriage.
There is no top ranking of states that don't allow same-sex marriage.
New Jersey and New Mexico have no statutes, pending laws, constitutional amendments or pending court decisions on the matter.
Effective June 26, 2015, same-sex marriage is legal in all US states and territories, although most started earlier than that.
I don't think you can. You either has to be single or married to adopt. Just living together is neither. if you are in a samesex relationship and has gone through partnership might be possible though.
Anyone can do anything they want to as long as they truly want it. No, in Islam having a boyfriend/girlfriend type of relationship is not allowed whether your a male or a female and whether the bf/gf is Muslim or not. If you have anymore questions regarding the matter, just ask and I'll be happy to answer them. i gree in islam having a boyfrnd or a grlfrnd is not allowd but today no youngr generation follows it .....so if a muslim girl personlly like a non muslim boy...then it is not allowd in islam.....u cannot marry him unless he accpts islam...:)