The Federation of American Zionists (which in 1917 became the Zionist Organization of America) met July 1-4, 1906 in a resort in the Catskill Mountains, about 120 miles north of New York City.

The convention was held in the Fairmount Hotel in Tannersville NY.

Dressed in their best, the custom at Zionist conventions, those attending the convention gathered on the hotel lawn for the picture shown below: the Tannersville photo.

From an old picture postcard found on eBay

This rare picture is a Who's Who of early American Zionists. Rabbi Stephen S Wise, a founder of the Federation of American Zionists, is the first man on the right in the first row. The women behind him in the second row include Masliansky's wife Yetta and their three daughters..

Source: The New Palestine,  a weekly paper published by The Zionist Organization of America. February 28, 1936, page 8

Seated in the second row at the left, is white bearded Rabbi  Solomon Schechter PhD, then the president of the Jewish Theological Seminary of America, who would later found the Conservative movement.

Next is Rev Zvi Hirsh Masliansky, the foremost Jewish speaker of the day. Expelled from Russia for his ardent Zionism (he introduced Chaim Weizmann to Zionism), he traveled throughout Jewish America, speaking in Yiddish to huge crowds and recruiting new members of the Zionist organization.

Then Rabbi Judah Magnes who that year would found the American Jewish Committee and was a founder of the New York City Kehillah effort.

In the front row, third from the right, his feet between the "M" and "O" of FAIRMOUNT, wearing knickers, hands clasped on his right knee and not looking directly at the camera is 13 year old Abraham Silver. "Abe" addressed the convention as leader of the Herzl Zion Club, the first Zionist youth organization. When he entered Hebrew Union College five years later, "Abe" Silver became Abba Hillel Silver.