Edwin Gaustad, a preeminent scholar on the separation of church and state who did groundbreaking work mapping the nation's religious landscape, has died. He was 87.

Gaustad died March 25 of natural causes at an assisted-living facility in Santa Fe, N.M., said a daughter, Susan.

"He did incredible work as kind of a geographer of American religion," said Leigh Eric Schmidt, a Harvard University professor. "He did this big atlas about what the American religious scene looked like, county by county, over a long stretch of history." The result was a first, the "Historical Atlas of Religion in America," which provided Gaustad with a rare scholarly surprise when he completed it in 1962.

"I thought we would be a much more homogeneous country religiously," he told the Santa Fe New Mexican in 1996. "We aren't." Gaustad was also prominent among a few historians in the mid-20th century who broadened the study of religion in the United States from theological schools to a wider university setting, Schmidt said.

After he joined the University of California, Riverside, in 1965, Gaustad was instrumental in establishing the university's religious studies program, said June O'Connor, a professor of religious studies who worked with him at the school.

"He was a scholar's scholar," O'Connor said. "Scholars really appreciated his work and the scope and expanse of his work and productivity." Yet Gaustad wanted his work "to make the historian's voice count in public debates of church and state," Schmidt said.

Gaustad was a leading expert on America's Colonial period, especially in the areas of religious liberty, pluralism and dissent.

He wrote more than a dozen books on religious history. They included "A Religious History of America," a popular 1966 text that was last updated in 2002, and "Roger Williams," a 2006 biography of the theologian who helped found Rhode Island and the Baptist church.

Latest Videos