Supporters of traditional marriage rallied outside of the U.S. Capitol on Sunday. The group of more than 150 African American pastors and laymen called for the definition of marriage as the exclusive union of one man and one woman.

The rally, which was sponsored by the National Organization for Marriage, was the finale to a series of similar rallies held across the country this summer.

The group also wants to see Washington D.C.'s same-sex marriage law overturned through a voter initiative.

"Same-sex marriage is not a civil right -- it is a civil wrong," Bishop Neavelle Coles of the Church of God in Christ told the crowd.

The city's board of elections and ethics has ruled against a ballot measure to let the voters decide if gay marriage should be legal.

Some of those who attended Sunday's marriage rally plan to appeal the matter to the U.S. Supreme Court.