Two hundred years ago, in August 1806, Samuel J. Mills, a first-year student at Williams College in Massachusetts, and four Christian friends gathered to pray in a maple grove near campus. Thunderclouds threatened, so the students sheltered under the eaves of a haystack. As the rain fell, their conversation narrowed to the need for American missionaries in Asia. Exhorting his classmates to consider God's call to foreign missionary service, Mills said, "We can do this if we will."

The first American student missionary society began in September 1808, when Mills and a group of other students formed a community called the "Brethren." After graduation, Mills and James Richards, one of the students who had prayed under the haystack, and some seminarian friends petitioned the General Association of the Congregational Church to establish the American Board of Commissioners for Foreign Missions. The first North American missionaries set sail for India in February 1812—fewer than six years after the Haystack Prayer Meeting.

Missions fervor spread quickly among collegians. By 1856, 49 of the 70 colleges in the United States with Christian organizations had a Society of Inquiry for the advancement of foreign missions. In December 1888, the Student Volunteer Movement for Foreign Missions (SVM) was established in New York with the slogan, "The Evangelization of the World in this Generation."

Like many other missionary slogans, this one didn't work out quite as intended. The world has not yet been evangelized, of course, and the remnant of the once vigorous SVM eventually died as its focus gradually shifted from overseas missions to political and social concerns in North America. But while the SVM was withering, another campus-based ...