At least 20 friend of the court briefs have been filed in appeals of rulings overturning gay marriage bans in Indiana and Wisconsin, including one by a group of churches and another by 10 states' attorneys general.
The brief filed by the attorneys general argues that society should decide whether same-sex marriage is acceptable, not the courts.
Another brief filed by the U.S. Conference of Catholic Bishops and groups representing four other churches argues that marriage between a man and a woman is God's will.
Most of the court briefs side with Indiana and Wisconsin. The two states are appealing federal judges' rulings that overturned their same-sex marriage bans.
Most of the briefs were filed this week with the 7th Circuit Court of Appeals, which is hearing the combined case.