Yes, in November 2006. The amendment says:
A marriage between a man and a woman is the only domestic legal union that shall be valid or recognized in this state.
This amendment was struck down as unconstitutional by the Federal District Court on May 13, 2014.
No. In 2006, the Constitution of Latvia was amended to explicitly prohibit same-sex marriage.
No. No such amendment has been made.
No. No such amendment has been made.
No. No such amendment has been made.
No. No such amendment has been made.
No. No such amendment has been made.
No. No such amendment has been made.
No, not exactly. In 1998, the state constitution was amended to permit the legislature to ban (or, presumably, not ban) same-sex marriage. The legislature afterwards banned it. The amendment says:The legislature shall have the power to reserve marriage to opposite-sex couples.
No. No such amendment has been made. On November 6, 2012, the electorate of Minnesota voted NOT to amend the state constitution to ban same-sex marriage.
No. No such amendment has been made. Same-sex marriage was legalized in Iowa beginning April 3, 2009.
No. No such amendment has been made. In fact, same-sex marriage was legalized in Maine on November 6, 2012.
No. No such amendment has been made. Same-sex marriage was legalized in Washington state on November 6, 2012.