The Wisconsin Assembly added a measure to ban civil unions and marriage for gay and lesbian families.
Fair Wisconsin featured local speakers who reflected on the need for legalized civil unions.
About 70 people showed up at Christ Church Cathedral to learn what they can do to spread the word and get others to vote against the ban.
This is one of the very few times Wisconsin is trying to make a constitutional amendment.
"The amendment goes too far by banning civil unions and seriously jeopardizing the ability of public and private employers to offer domestic partner benefits,” said Mike Tate, Fair Wisconsin campaign manager.
Fair Wisconsin is planning to open field offices in at least nine cities in the next couple of months.