Zach Wahls, Gay Rights Activist, Appears On 'The Daily Show' To Talk New Book (VIDEO)

Zach Wahls' passionate, viral defense of his parents' same-sex marriage is now available in book form.

Wahls, then a 19-year-old engineering student at the University of Iowa, gave a rousing speech in favor of same sex marriage before the Iowa legislature in 2011. Shortly after, he made appearances on CBS and MSNBC, and began sharing video of his three-minute testimony to their members.

He discussed "My Two Moms: Lessons of Love, Strength, and What Makes a Family" with Jon Stewart on "The Daily Show" Monday evening.

Wahls has put his college experience on hold to spend more time campaigning for LGBT rights. One of the projects he's promoting is a program called "Out To Dinner," which tries to get straight couples and same-sex couples to have a meal together and get to know each other.

Check out his original testimony from February 2011 below.