The proposed constitutional amendment would ban the state from honoring civil unions and define marriage as a relationship between a man and a woman in the state's constitution.
Same-sex marriage is already prohibited in North Carolina.
On Saturday, an all-day festival was held on Fayetteville Street in Raleigh with the hopes of swaying voters to oppose the amendment.
The festival was sponsored the LGBT Center of Raleigh, Alliance of AIDS Services-Carolinas, and Equality NC.
But those in support of the amendment were also urged to vote early. The grassroots efforts on both sides of the issue fueled the debate and caused long lines at early voting sites.
"I voted for it, so I voted early," said pro-amendment supporter Gary Birdsong. "My church that I go to, and most churches that I know of, are voting for it. "
Voter Jacob Warwick said that if the amendment passed, it would write discrimination into the state's constitution.
"As a gay person, I couldn't, in good conscience, vote for an amendment that would deny me my rights at a systematic level," he said. "It's just criminal that they would try and put this discrimination into a constitution that's meant to give rights to citizens instead of taking them away."
On Sunday, the proposed amendment was discussed in many churches throughout the state.
But not all religious leaders are in support of the amendment.
An Episcopal Priest, Rev. Lorraine Ljunggren said people across the spectrum are praying for various outcomes.
"At St. Mark's Episcopal Church, we've taken the position, which is a legal position to take, that Amendment One does not respect the dignity of every human being," she said.
Voters in favor or in opposition of the amendment could not be distinguished by political party either.
"If you look at the official statements of a lot of the Republican congressmen and state congress, you'll see that they're actually voting against," said Warwick.
The debate has caught the attention of political heavyweights.
Beginning Monday, registered voters will receive robo-calls with a recorded message from former President Bill Clinton stating that the amendment would damage several aspects of the state's viability.
Clinton stated that the amendment will affect the state's ability to attract new businesses and will take health care from children. He also stated it could diminish the state's laws protecting women from domestic violence.
The state's primary election is Tuesday. Polls will be open from 6:30 a.m. to 7:30 p.m.
Click here for the State Board of Elections information on voting in North Carolina.