The Jacob Rader Marcus Center of the American Jewish Archives is the repository for more than 10 million pages documenting American Jewish history. The Cincinnati campus of Hebrew Union College-Jewish Institute of Religion houses the collection. Gary P. Zola is executive director.

The American Jewish Historical Society is in the Center for Jewish History in New York City. It is a collection of American Jewish holdings from the 16th century to the present. Paul B. Warhit is president. Contact Nicole Straus.

Wikipedia keeps its page on same-sex marriage updated with background, links, state-by-state information and charts. Wikipedia also has a page about Christian churches around the world that have approved same-sex marriages. As with any open-source website, information on Wikipedia should be confirmed before it’s used.

NPR has posted a timeline of significant developments in the debate from 1972 through 2012.

Joey Weisenberg is the creative director of the Hadar Center for Communal Jewish Music. He is a mandolin player who is bringing ancient Jewish nigunim, or wordless rabbinic hymns, back into synagogue music. He was named to Jewish Week’s “36 Under 36: The Next Wave of Jewish Innovators” (scroll down).

Daniel Sieradski is the founder of Jewschool, a blog that covers everything from politics to religion to art from a Jewish perspective. It has 50,000 readers and contributors from 80 countries. He was named to Jewish Week’s “36 Under 36: The Next Wave of Jewish Innovators.”

Rabbi Naomi Levy is the founder of Nashuva, a Jewish worship community in Los Angeles. Levy is widely credited with finding innovative and creative ways of engaging unaffiliated and disaffected Jews with their faith.

Isaac Jerusalmi is a professor emeritus of Bible and Semitic languages at Hebrew Union College in Cincinnati. He wrote the introduction to Stanford University’s digitized Ladino library.

Gloria Ascher is an associate professor of German at Tufts University in Medford, Mass., and the only American professor who offers regular college courses in modern Ladino.