Election Day proved to be a monumental day for gay rights supporters after Maine and Maryland became the first states to legalize same-sex marriage by popular vote.
Meanwhile, in Minnesota, gay rights groups also scored another victory in the polls when voters rejected a proposal to define marriage between a man and a woman in the State Constitution, a measure that is featured in constitutions in 30 other states, according to the New York Times.
Final poll results in Washington, the fourth state voting on same sex marriage on Election Day, were not available Wednesday morning, the New York Times reported, but with half the votes reported, the proposal to legalize gay marriage had a small majority.
Thus far, six states and the District of Columbia have legalized same-sex marriage through judicial or legislative action, but voters shot down the measure at the polls more than 30 times consecutively.
Gay rights groups hailed the Tuesday election victories as a major step forward in the gay rights movement.
"The tide has turned - when voters have the opportunity to really hear directly from loving, committed same-sex couples and their families, they voted for fairness," Rick Jacobs of California-based gay rights Courage Campaign, a group, told the Associated Press. "Those who oppose the freedom to marry for committed couples are clearly on the wrong side of history."
Maine's referendum was the first time that gay-rights supporters put same-sex marriage to a popular vote, the Associated Press notes. Supporters for the measure collected enough signatures on petitions to schedule the vote. The goal was to reverse a 2009 referendum in Maine that turned down a gay-marriage law enacted by the state legislature.
While in Maryland, voters upheld a law allowing same-sex marriage that Gov. Martin O'Malley signed into law last March.
"We have made history for marriage equality by winning our first victory at the ballot box," Chad Griffin, the president of the Human Rights Campaign, told the New York Times. Griffin's group raised millions of dollars for the measures in the four states.
Fred Sainz, vice president of communications with the Human Rights Campaign, told NBC Politics that President Barack Obama's support of same-sex marriage was a big reason for their victory.
President Obama, who won re-election to a second term Tuesday, has said that his decision to back marriage equality was made after speaking with Americans including servicemen and women he met during the work to end Don't Ask Don't Tell. Republican candidate Mitt Romney has repeatedly stated through the election campaign that he would only support marriage between a man and a woman.
Opponents of same-sex marriage, however, did not see Tuesday's election as a signal of change in the way that Americans view marriage equality.
"For the gay marriage groups to win in the most liberal states is not a tipping point at all," Brown said.Brian Brown, president of the National Organization for Marriage, told NBC Politics.